not talking entire drive, though. Just useless crap that he wants to just keep around like images and such. Put them into a folder and then compress that folder. Things like BMP's and stuff. Compress that one folder only. Thats the nice thing on NTFS, you can compress single folders and not have to do the entire HDD, and images are hard to corrupt. Hell, you could also do sound files, too. Just dont compress and dat files. So, make sure the folder doesn't contain anything like that. Say, you were running SQL and you wanted to compress some old SQL data bases. Go right on and do it I say, its fairly safe. Again, just stay away from system files.