File Undelete and renaming

I accidently left my pen drive plugged in the pc when i restarted it…when it did, windows chkdsk utility ran and moved all files in my pen drive to a folder named FOUND.000 and renamed all of them as FILE001.CHK, FILE001.CHK and so on…
I know all of them are doc files… so i can view them with word viewer but i want to rename the first part of the files , not the extension… please suggest a way or application for doing it as there are about 1000 files in ther.. I have been renaming them for 3 hours now..(opening each one and looking what it was) and still about 250 files are done and most are remaining…
please anyone can help me??
Answer #1
You could use UnCHK or similar app (FileCHK,CHK-Mate) , but you will still have to rename the individual files, this will give them the correct .doc extension though
http://www.ericphelps.com/uncheck
Answer #2
ant renamer
http://www.antp.be/software/renamer
works a treat for me