FUCKKKKKING FUCKKKKk

*former IT guy chimes in*

joe, you never mentioned if you were on a laptop or a desktop...if the answer is laptop, then most likely, your hard drive has cancer :erk:
desktop hard drives are WAY less prone to the "slow death" simply because hard drive slowdeath is usually caused from it getting bounced around...and because they're bigger/sturdier, etc.

yes, windows and i believe just about any modern file system works the same in that when you delete a file, its content isn't immediately erased. the file system (ntfs, fat32, different formats of file system) is a map at sector0 on the hard drive that contains a plot of every file/directory on the hard drive, and tells where the "clusters" (chunks of file content) can be found on the drive. long story short, if things are "vanishing" ...they're still recoverable, sortof...but the odds of re-assembling a big .wav file in the order it was created are pretty low, because it's usually in a gazillion different clusters scattered all over the drive, and with the deletion of a file in the file system, also goes the map of how to read and re-assemble it. take into consideration how big and complex a DAW project is (gigs worth of tiny snipped up .wavs file that don't work if they're not in order) and data recovery is...conceivable, but ... usually unlikely, and costs obscene amounts to do correctly.

it could also be viral but that's unlikely. setting up a DAW PC 101, we all know it's best to keep our DAW station away from teh intarwebs... this removes the need for firewalls/mcafee and other resource gobbling crap, or any security software whatsoever, prevents shit from trying to sneak under the radar and install updates just in time to mangle the perfect take you've been waiting hours for...etc. and, ofcourse, eliminates the risk of getting nasty data-eating shit in your setup. separate youtube/facebook/porn station is necessary!!