I use Ztree.
Download at www.ztree.com. Shareware good for 30 days. Small footprint and doesn't mess with Windows.
Log every file on your hard disk by pressing the asterisk key (*) on the root of the deive.
Hit (G)lobal view. You now see every single file on your hard drive.
Press ALT-(S)ort, by (D)ate.
You can now go to the exact date/time that you were editing the file and see all files stamped at that date/time. It will be obvious which files are the ones that may be fruitful.
You can also (T)ag and (S)earch for a particular string within those files. Search for something that you know was typed in the document. You may want to try both Text and Unicode search.
I'd like to find a utility which could produce a listing of everything on a hard drive, complete with a CRC-32 of every file (including ZIP contents). This would make it possible to determine which files, directories, and drives hold copies or (in the case of directories and drives) "almost-copies" of other files, directories, and drives. This would make it much easier to keep good backups of things (one difficulty with backups is determining when an old backup really contains nothing of value; if a file gets corrupted, it may be necessary to go to an old backup to get a good version, but if one could tell after doing a new backup that the file hadn't changed since the old one, that danger could be greatly reduced.