I had about 15 files saved as File0000.chk through File0014.chk. PLEASE CHANGE CATEGORY IF I POSTED IN THE WRONG SECTION. First I tried renaming them with the likely extensions I use most often, such as .xlsx and .docx respectively for Excel and Word. This successfully recovered over 1/2 of my files. Now I have 5 files remaining, which aren't yet recoverable, even trying other extensions like .pdf, .txt, and .jpg but no luck on those. I believe most of my files are .xlsx since I viewed them in an editor and see the words "worksheet" which are normally related to spreadsheets. I also downloaded and ran the free UnCHK at ericphelps.com and this recovered 1 more file. The purpose of the program is that it automates the filename extension renaming, so that you don't have to do it manually using trial and error to find the correct file extension. WHAT ELSE CAN I TRY TO RECOVER THE REMAINING 5 .CHK FILES? Recover CHK Files With my 5 remaining files, I tried joining some of them, thinking that that might solve something, but that hasn't worked yet. ANY OTHER SUGGESTIONS? I haven't yet tried joining different combinations of 3 file fragments into 1, as the permutations of 3, 4, or 5 files would be time consuming. Here is an example of the code to join 2 files. copy /b file0099.jpg + file0001.chk test.jpg The above would take the partially recovered file0099.jpg and add the contents of file0001.chk to it, storing the result in test.jpg. You'd then have to try opening the test.jpg file to see if that helped.