Disk Cleaner / Eraser

Hi,

Can anyone advise of any free programs to download to "clean" my hard drive? I want to completely remove all traces of internet activity for security (banking details / passwords / pins etc) reasons.

Which program is the best for destroying all evidence off the hard drive? Note: I don't want to remove all my current favourites etc or my documents, only things which I have already deleted and passwords / codes etc for online banking and transaction through e-bay etc.

Thanks.

 

Ccleaner is the crowd favorite here.

http://majorgeeks.com/download4191.html

 

Thanks a lot!