@AW: Please forget about defragging. Now.
Ever heard about disk forensics? They cut open your disk in a clean room and check the bits one at a time, and they can recover drives run over by cars for anything between 400€ and a few thousand Euro.
The only way to be halfway sure that unencrypted data can't be recovered is to use some data burning tools (they overwrite the data with random bits _multiple times_), and even that isn't safe, because harddisks optimize a bit too eagerly these times and might just point the data burn tools to different bits even though they say that they write to the same ones.
The way to be mostly safe is to create an encrypted partition/section on your drive and save the data into it.
If you then want to delete it, you just have to delete and overwrite the encrypted partition, because encrypted files can't be recovered from remaining shreds, while for unencrypted files small shreds suffice to show which fiels where there.
Be vary of incomplete files, though. They must go into the encrypted partition, too.
And make sure you read up on the encryption algorythm you use. If it encrypts in smaller parts, then you must make sure that every part is getting shredded.
And while I'm at it: You shouldn't download copyright infringing files in the first place. And even less in unencrypted networks. They just need to bust the one you downloaded _from_ to get enough evidence against you. |