This has been an excellent read.

I just thought I'd follow up on a couple of the above points, even though the thread is very old.

First, as regards wiping software: I haven't tested a whole lot of the wiping software out there. However, I did have a chance to test Eraser 5.7, the current version of the file Datsun mentioned above (freeware, available from http://www.heidi.ie/eraser/). I created a test text file and using both the free "Disk Investigator" program and Winhex, navigated to the location on my hard disk where the file was kept. I verified the file contents using the view of the raw disk data. I then did a regular delete of the file, which I then verified left the data on the disk intact.

I followed this test with creating another text file, and once again navigated to the data on the disk. This time, I wiped the file using Eraser. A refresh confirmed that the data on the disk was wiped clean (all the way to the end of the last cluster). In other words, it worked as advertised; there was nothing left to recover.

As regards spider, above: tests of my own have led me to the conclusion that if one simply starts Windows and clears Internet cache files and history, the data remains intact in Index.dat files. However, if you run Internet Explorer first, then close the program and clear the cache/history without closing Windows first, the Index.dat files are cleared.

Regardless, I've written a short logoff script which secure deletes the Index.dat files as well as any Internet Explorer cache/history/cookie files. The script uses Eraser, the program mentioned above.