Did you securely delete all Thumbnails ?
Did you securely delete all Windows data held in Windows files and Registry hives that might have allowed Windows to rebuild the thumbnails ?
In my early years with XP I would look at absolutely all files (including hidden and "not accessible") that had been modified "today".
I quickly decided that certain files were in a constant state of flux because the O.S. was always fiddling with itself,
and I refrained from detailed inspection.
One file attracted my attention and I inspected its contents.
I found reference to a strange file on a strange path of a non-existent drive P:\
I went crazy at the thought that malware had installed a pseudo drive.
Then I discovered ROT13 and deciphered P:\ as Microsoft's encryption of C:\,
and the strange path decrypted to a new path for my new application.
http://blog.didierstevens.com/2006/07/24/rot13-is-used-in-windows-you%E2%80%99re-joking/
After I have run CCleaner and observed what it removed I might sometimes click ANALYZE a second time,
and occasionally the O.S. will have recreated Thumbnail Cache.
Who knows what else the O.S. is remembering of your past actions ![:(]()
Wiping free space should remove the files that had been deleted, but the system still remembers what you did and where,
and the system can recreate the thumbnails as evidence against you.
You are wrong if you think that wiping free space will protect you from the F.B.I. ![:o]()