Important: Save yourself some trouble. If you already know the extension of the file(s) you want to get back, just rename all your CHK files to the desired extension and see what works. The programs here are for when you have way too many CHK files to test or when you have way too many different file extensions you want to recover. So what is a CHK file? Well, any time a program or Windows crashes, any files that were open are not closed properly. Part of closing is writing all the file location information in all the right places. Without this info, Windows can't find all the parts of the file.
If the contents of a CHK file can not be identified, you have the option to extract all the readable text from the CHK file. This option is useful to recover information from a CHK file that is perhaps not intact enough to be recovered completely as a known file type. Download CHK-Mate. Jul 9, 2013 - STEP: 5 - CONVERT CHK TO JPEG (EXAMPLE D: recover chk files. STEP: 6 - TYPE ren *.chk *.jpeg. Example: (if chk files is D: folder name.
When SCANDISK or CHKDISK is run, all the parts are identified as 'lost file fragments' and converted (if you want) into CHK files. Stuff crashes all the time.
If you only run SCANDISK once a month, you get a month's worth of old crash junk. If you were working on (and lost) something important just before a crash, you might want to try to recover any data from any CHK files that exist. On the other hand, if you aren't in a state of panic over lost data, just delete any CHK files. A handy tip: Keep your disk defragmented. That way if you ever do lose it all, the lost file fragments will be more likely to be complete files.
File Recovery and Viruses This is unavoidable. If file is infected and it gets recovered, your antivirus may complain that the recovery program wrote the virus. Which is true. And really, a fair percentage of all recoveries are due to a poorly-written virus causing file system problems. So when the recovery program renames a file from 'chk' to 'exe' and your antivirus pops up, please remember that your problem is the recovered file, not the program that recovered it!
Welcome Competition! A nice guy named Martin Kratz wrote a utility to compete with my UnCHK program. Amazingly, he sent me the source code. I compiled it and am offering it here for your consideration. Pay attention: Read the next paragraph about MSVBM50.
Apparently some ne'er-do-wells are using the normal 'file missing' message from Martin's FileCHK program to scare you into installing something bad. Don't be fooled. The respected analysis has been giving FileCHK a clean bill of health since 2008. Both programs need the Visual Basic 5 runtime files. If you receive a error, you can get the required files from. Now you have two open-source CHK file recovery programs to choose from!
I'll do a side-by-side comparison: (Eric Phelps) (Martin Kratz) Out-of-box supported file types JPG PSP PSD GIF ZIP CAB EXE DLL OCX WRI BMP DOC PPT XLS PDF RTF HTM WAV MID AVI RAR TIF MP3 WPD FPX EPS CLP 3DS TIF EXE BMP SWF PSD AI GIF PST CAB RAR CHM MID PDF ZIP HLP MP3 DWG MPG LNK URL HTM JPG TTF MDB MOV QT DOC XLS RMI WAV AVI CDR TXT ASF Can add more file types? Yes, just drag a good file and drop it on the program (only applies if that file type has a standard header).
Alters CHK files? Makes a copy of the CHK file and gives the copy the correct extension. Renames the original CHK file so it has the correct extension. Recovers any CHK file?
Anything with a CHK file extension is checked. This makes things more flexible. Only acts on files named like 'FILE####.CHK'. This makes things safer in case there are legitimate files with CHK extensions. Identifies files by file header? Also looks inside some files in an inexact way to try to discriminate between different types of files that share the same header.
Also reads inside the file in a more exact way to tell different files that use the same header apart. Looks inside CHK files to recover cross-linked files?
Yes (if you choose the 'hard disk' option). Looks inside CHK files to recover embedded items? Yes (if you choose the 'embedded files' option).
And it has a percentage done indicator so you'll know whether you have time for lunch. You won't believe it. Has cool graphical interface? It has an interface. Except for the 'Done' message when it finishes. It works for me. It's too simple to break.
Selectable directory? You pick what directory CHK files are in and what directory you want recovered files to be in. The program itself can be anywhere.
Put the program in the same directory as your CHK files and run it. False negative or false positive recoveries? About a quarter the files it recovers are either mis-named duplicates (which can't be opened) or fragments (which you might not be able to open).
But it allows you to choose scan depth options so you can decide how to trade off missed files and false detections. Might not recover a file fragment and never recovers a cross-linked file, but the files it does recover can more likely be opened without errors.
The UnCHK program link above (at the top of the comparison table) is for version 3. Was built for Windows 2000, but might work on computers as old as Windows 95 was built for Windows 95, but might work on computers as new as NT4 was built for Windows 3.1 and might work on computers as new as NT4 I recommend you use the newest version that applies, because the older versions really needed the fixes and features that are in later versions! Other free recovery programs A generic file and disk recovery program.
From the people who also provide the free Recovers jpg, tif, bmp, gif, crw, raf, raw, orf, dcr, mrw, nef, x3f, avi, mov, wav, and dss image and multimedia files from most digital camera removable memory devices. Recovers GIF, JPG, TIF, WAV, MOV, and CRW. This dedicated image recovery utility was made to recover digital camera data, so it recovers an entire drive. Which means use it on a mounted camera or CF/SD card, not to recover a few CHK files on a normal hard drive! If you've lost your entire hard drive and you already tried fixing it with ScanDisk, then UnChk and FileChk (or something like them) may be your only hope. Once you run scandisk or do anything else to a bad drive (like running a program or copying a file), you make changes to the 'File Allocation Table' (FAT) that helps track where the files are (were) actually stored. If you lost your entire hard drive, your FAT probably got damaged by an accident that killed Windows while it was busy updating the table.
If you use Scandisk, it goes through and builds an entirely new file allocation table, permanently replacing whatever was left of the previous one. Which eliminates all hope of every fixing the original FAT. If all your recovered files only seem to be pieces, it's because your files are (were) fragmented. All hope is lost. If you have a viewer that lets you see the good part of a bad file (like you can see half a picture or hear half a song), then it will take you about one solid month of work to recover a single file. If you can't see partial files and you have more than a few fragments in a file, you are on the wrong side of a big factorial.
There will be nothing but neutrons and black holes in the universe by the time you get anything recovered. You're better off starting over. Your only hope is that you were hit by a particular kind of virus. Maybe a virus made a separate copy of your FAT and hid it in a 'bad' sector of your hard drive.
The virus then put a fake FAT in its place. If the virus suddenly got killed (usually because a newer virus tried to take its place), then nobody would know where the real FAT was hidden.
If that's what happened, you might be able to use an anti-virus program to find your missing FAT. A clue would be if ScanDisk or CHKDISK says you have 'bad' sectors on your hard drive. There are also some dedicated disk recovery programs that are familiar with common hiding places for FAT tables. If you ever lose your entire hard drive again (and you know it's badly fragmented), turn the computer off, pull out your bad hard drive, run out to the store and buy a new hard drive and a recovery program. Install and format the new hard drive in the computer and make it the primary drive. Reinstall an operating system on the new hard drive. Install the recovery program on the new drive.
Then install your bad drive as a slave. Once the recovery program is running, tell it to try to repair the FAT and preserve the original file names as much as possible. If you're lucky, the recovery program might even be able to fix your bad drive. If not, you at least stand a good chance of at least getting your data copied onto your new drive.
By the way, the better recovery programs (and better computer techs) NEVER write to or change anything on a bad hard drive unless they are VERY sure they can bring the bad hard drive 100 percent back to normal. I can't recommend a disk recovery program.
It's not that I won't recommend a program, but I can't recommend a program. I have almost no experience with them! Most of what I know is based on a vendor's reputations and on what I've heard. The first one that comes to mind is (Norton Utilities). I also remember 'LostAndFound' from PowerQuest, but I see they've been purchased by Symantec. Maybe you can find someone (other than me) who downloaded or bought it while it was available.
PowerQuest/Symantec now Total Recall's. I tried it and was impressed, but found they wanted about a hundred dollars for the first gigabyte of recovered data. Steve Gibson's disk recovery software has a very good reputation. SpinRite will work on any file system to recover low-level hard-disk errors. Another great company is. They mainly do paid disk recovery, but they also sell programs so you can do your own disk or file recovery. Is another company with a good reputation.
Ask almost any sysadmin, and you'll find at least one of their tools being used. Sysinternals offers and for limited transfer of NTFS files from a bad computer. Sysinternals gives most of their utilities away free, but the unlimited recovery versions of their software do require you to spend something!
Finally, there's, a company I only know of because of a recommendation. RunTime has several disk recovery programs. The big reason I include it here is that they support (and have links to and from) - a method of creating a bootable CDROM to host your recovery programs. The link from Bart's site to RunTime really raises RunTime's credibility. Having a bootable CDROM around in case of problems is such a great idea. And being able to customize the CD to include the programs you want makes it an even better idea! My personal experience with disk recovery was when I managed to wipe a 20GB disk (by foolishly installing and uninstalling a FAT disk encryption program).
I had a feeling all the data was there, but that the FAT table was bad: Windows 2000 wouldn't see the drive, and the disk manager showed it existed with an unknown partition type. I tried, and while it was a little awkward, it did convert my hard disk from the inappropriate FAT12 into the correct FAT32, thereby recovering the hard drive. That set me back about 40 bucks, but I had darned little choice - the disk that got lost was the one I had all my disk recovery software on. No backups, of course! I searched PC Magazine for software reviews and found this page: I searched Google with words like 'file disk recovery data download' and I was shocked to see how many disk recovery programs are out there! Here's a few in no particular order and with no recommendations. Most offer a free preview version that will show you the data they can recover (after you pay for the full version): MP3 Files Virtually everybody I know who's lost a bunch of MP3 files knows which files are the MP3 files they've lost.
Really, you don't need either of the above UnCHK or FileCHK programs! Just rename the files so they have an MP3 file extension. Then see which ones actually play!
The next problem is how to rename all the MP3 files by song title and/or artist. Luckily, there are several perfectly good MP3 ID3 utilities out there that can automate the renaming task. You can search the web and find several, but my favorite software site is SourceForge (because like the UnCHK program, all their software is free and open-source). SourceForge has the following Windows MP3 ID3 projects: Martin's Explanation on FAT and Filenames Filenames are contained in ordinary files with the DIR attribute set, which DOS and Windows recognize as directories / folders. There you find for each file contained in that directory: DOS 8.3 file name in ASCII, Win Long file name in Unicode, file size, Create/Modify/Last Access Date, attributes (such as ReadOnly, Hidden, Archive, System, and DIR meaning actually a subdirectory, not a file) - and the disc sector cluster number of the file's first fragment.
With the latter info, the OS goes to the FAT to find out the cluster numbers of all subsequent fragments - that's all a FAT does. It describes clusters - whether they're free, bad, or used. It's possible to use some sector-level disc editor to search lost directories for files with 1st cluster numbers matching the1st cluster number of a given FILE####.CHK, but that that would probably take weeks (it has to be done manually) and you can totally forget it if the disc in question is your C: drive.
There are FAT-16 and FAT-32 file systems. FAT-16 FAT entries are simply 2-byte unsigned integers and hence can hold values of up to 2^16-1 = 65535 for each cluster. That's why we have clusters - on discs having more sectors than that, Gates had to lump subsequent sectors together in clusters to scale down the numeric values. If a cluster is used, the FAT entry of that cluster gives the number of the cluster where the next file fragment sits, or some special value if the cluster has the last fragment of a file.
However, cluster sizes in the MByte range would be a waste of disc space because of slack. Imagine a 300-byte Iexplorer favorite taking up 1MByte on a 65-GByte disc because it has to combine 2048 512-Byte sectors into 1 cluster in order not to have more than 65535 clusters.
So Gates came up with FAT-32 - to get cluster sizes back down to at least tens of kBytes. By the way, that's why 'file size' and 'size on disk' are different ballgames (last fragments of files not filling up their entire clusters), and that (among other things) is also why Gates should be serving =10 yrs in a boot camp for not combining all favorites in a single bookmark file, like Netscape does (at least he combined all those pesky WIN3.11 INI files into SYSTEM.DAT and USER.DAT).
After reading Martin's explanation, you may see how after CHKDISK or SCANDISK 'fixes' your hard drive, NEITHER of our two recovery programs will get your original file names back. Because both our programs are ignorant of any recovered directory files that might contain the original names. We both treat a recovered directory file as just another file.
One of the things about Windows is sometimes it seems to do things in a way that doesn’t really make a great deal of sense. One of those situations is when an improper shutdown is detected or something like a USB stick is detached too quickly and Windows decides it needs to for errors, which in itself is not a problem. If you decide to skip, Windows will continue to ask you to scan because the is still set on the drive. You let Chkdsk or Scandisk run and it will repair any problems with the file system and recover or repair any corrupted files affected because of it. The issue arises when you want to look at the files to see if any personal or important data has been affected because everything recovered by Chkdsk or Scandisk now has a generic filename of File.CHK placed in a Folder called Folder. at the root of your drive!
The odd thing is Windows has no utility or built in function to let you find out what these newly renamed files were before it changed them all to CHK files. Although sometimes a CHK file cannot be recovered successfully because it has been too badly damaged, many of them can be used again, but you need to find out what type of file each one is and the correct extension needs to be applied. If Windows crashed while editing a document, there is only 1 CHK file and your document is missing, then renaming the file to mylostfile.doc could be worth a shot, but in most situations you won’t be so lucky or there’s a lot of files that need checking. Fortunately there are third party tools around that are able to help you recover CHK files by checking the headers of the files and identifying what the type of file is and what its original extension should be. Here’s a selection of ways to help you out. UnCHK UnCHK is a free CHK file recovery tool that is able to help you restore CHK files for around 25 different file formats to their original extension.
It can identify some of the most common types including audio, video, images, archives, executable files and documents. UnCHK also has a valuable feature of allowing you to add your own file type extensions by simply dragging and dropping a known good file onto the program’s icon. It will then be recognized from then onward when scanning CHK files. Run the tool and it will ask you for the directory where the CHK files are and then a destination directory. The Scan Depth window gives various options about the recovery method; Whole Files will look at each file and check for a recognized signature, Embedded Files can pull objects like images from inside the CHK files and Floppy/Hard drive can check for cross linking in the files. The program was tested and worked fine on Windows 7. FileCHK FileCHK is about as simple a tool as it gets, and has no options or interface at all.
It simply scans your CHK files and renames them with the correct file extension if a recognized file type is detected. Around 30 types of file are supported including the most common multimedia files, images, some common archives, executables and Office/text files. To use the tool all you have to do is place it in the folder where the File.chk files are, then run it. The process takes no more than a second or two and the files it recognized will have been given the appropriate extension. Because it renames the original files automatically, it’s best to run the tool on a backup of the files in case you wish to try another utility here as well. FileCHK requires the installed to work.
CHK-Mate CHK-Mate has a wizard style interface that asks you where the CHK files are located, then asks where you want the renamed files to be saved as it creates a copy of them and doesn’t overwrite the originals. It will then examine the contents of the CHK files and determine whether they are known to the program, and if they are, will create a copy with the appropriate file extension. CHK-Mate only recognizes around 20 types of file by default although you can add custom types yourself. One thing we noted about CHK-Mate was just how slow it was in trying to recover the files, over 20 minutes to scan 18 CHK files in Windows 7. It did look like it had crashed several times but did eventually finish, and at the end recovered 13, about the same as the other tools here. If the contents of a CHK file can not be identified, you have the option to extract all the readable text from the CHK file. This option is useful to recover information from a CHK file that is perhaps not intact enough to be recovered completely as a known file type.
TrIDNet If you have some more obscure types of files on your computer that might not get picked up by one of the CHK file recovery tools, you might like to try to identify them with TrIDNet which has a good chance of helping out. Although it can’t rename the files for you automatically, TrIDNet can perhaps fill in some gaps if your CHK files remain unknown.
The tool itself is quite old dating back to 2004, but the database is still constantly updated meaning even the latest file types are recognized. Download the program and and unzip it, then download the definition files package and unrar the 1000’s of XML files into the TrIDNet main folder. Run the program and click on Rescan Defs to load them all in.
Then browse for, or drag and drop a CHK file to identify it. The display will give a percentage of the likelihood a certain file extension matches the file. As an example, the screen shot shows TrIDNet thinks the scanned CHK file is an EXE rather than a DLL, and it is correct. The.NET Framework is required and the defs files and program are downloaded separately. FiletypeID This utility works along the same lines as TrIDNet and uses the same TrID library and definitions to identify files by their type and not the extension, such as CHK files.
FiletypeID has a lot more modern graphical interface though with a couple of useful extra functions as well. Although it is relatively up to date, the program comes with the definitions already built in so isn’t fully updated by default. This is easily cured by clicking on Update Definitions from the program’s Help menu. The program is fully portable and usage is broadly the same as TrIDNet where you browser for or drag and drop a CHK or any other file onto the window. Click the Analyse button and it will give you a list of types and possible extensions with the most likely being the highest percentage entry. A useful button is Details which can give more in depth information about certain types of file such as video and audio encoding/bitrates and archive compression etc. Works on Windows XP and above.
Chk-Back From TRC Data Recovery, Chk-Back is an easy to use utility with a pleasant interface. It has support for some including the most common image, video, audio, executable, document and office files, as well as Windows Address Book, Outlook Store and Outlook Express mail store files. Although it does require installation, Chk-Back isn’t difficult to operate. Press the button to browse for the CHK files (usually in Folder. in the drive’s root) and it will show the files to be checked. Click Start and within a matter of seconds the process will be complete with a highlighted log file ready for you to save to a file if you wish or copy and paste elsewhere.
A saved log file and the corrected CHK files will be created in a new folder called “ChkBack Results” in the same folder as the original CHK files. Works on Windows XP and above. The Manual way Although obviously not the quickest or simplest method, one of the ways you can check and try to identify the CHK file is be by simply opening it with Notepad, or a Hex editor. All file types have a unique header in the first few bytes to tell one file apart from another, and although many will have unrecognizable characters at the beginning of the file, some contain a few characters at or near the start that can be recognized to help you identify what the file is. For example, “Rar!” at the start of a file is a WinRar archive, “ID3” means the file is an MP3 and “JFIF” in the first 10 bytes of the file means it’s a Jpeg image.
However, there are some more tricky ones to identify such as executable files have “MZ” at the start, but so do DLL files, screensavers, some font files, driver files and a few more. It therefore might not be a simple case of renaming a file with MZ at the start to.exe.
A similar problem happens with ZIP archives because although it has a simple “PK” at the start of the file, this could easily be a Word DOCX or Excel XLSX file because they are also simply renamed Zip files. Even game levels can sometimes be archived with Zip. If you want to try and identify a file that has gibberish characters or something not easily recognizable at the beginning, a useful manual way is: 1.
Open the file in a Hex editor such as. Highlight and copy the first 8 bytes or so of hex to the clipboard. Go to a website resource that lists the signatures for hundreds of different files, such as Gary Kessler’s. Another one is. Then use your browser’s search function (Ctrl+F) to look on the page for the hex value. If it’s not found simply delete a byte at a time from the search until it is found.
As you can see, the file was identified as a Windows Media file although it didn’t say which type exactly. At least we now know that trying the extensions of.WMA,.WMV or.ASF will most likely get the file to work. This method is quite useful if you want to learn how to quickly identify unknown files by simply looking at the first few bytes of them. The same thing happened to me. I inserted a 64gb Micro SD card into my StealthCam game camera, and it instantly corrupted tons of files. There’s no warning on the manual that StealthCam will instantly corrupt your card. There’s nothing on there stating that they require s proprietary file format.
I simply inserted it, then went back to check it and boom, all my files gone. I lost tons of data on a 64GB Micro SD in the process. Fully corrupted family photos and drone footage. StealthCam’s operating system sucks. Did you also have a StealthCam or what type was it? I will be buying new CuddieBack cameras after this.
I like the mesh architecture. This has happened to me twice 1st time after a power cut my computer restarted into chkdsk and 500 gb of my social work was corrupted, I mean the folders were still there, with the filenames, dates and even the exact file sizes and correct create/modify date but they just wouldn’t open so, I checked with a hex editor and found the information was all wrong it’s as if it had been mixed up? Now again I got up started my computer while I had a shower and again chkdsk started up and this time corrupted 50gb of social photographs, this is totally unacceptable these drives were both new top of the range western digital 4tb black caviars they were tested and had no problems either before chkdsk or after the problem both times was with chkdsk I am so upset about it as I know there was nothing wrong with those files and that all the information is still there, but somehow chkdsk has jumbled up the hexadecimal code? Is there anyone who can help me I really need these files it’s my life’s work. Yes I know I should have backed it up and I have many TB’s backed up but this work was not (I know, my bad!) but I invest in reliable equipment for holding this should and would not have happened had it not been for chkdsks buggyness. Any help advice appreciated HH.
Most valuable, thank you for this! By accident I found – for some at least – another solution. My external USB stick had suddenly lots of chk files. Trying unchk I got a “missing msvbvm50” mistake (easy fix: you get that file from microsoft). Yet I just opened the usb stick in my Linux – and guess what, pictures showed as pictures (little images^^), others were called “audio” and in Linux you saw even what type (green= ogg on my lubuntu, red = wav etc.). So I could rename the files or decide if I needed them all.
/ Those many of you who do not run Linux can run ubuntu, mint or lubuntu or whatever from a usb stick without actually installing it. I am aware that this is not the quickest solution, but I thought I mention it, as my Windows did not show any file type, Lubuntu does. All the best!