How to Permanently Remove Files from Your Hard Drive

With CCleaner

1. 
   Download and install CCleaner
2. 
   Open the tools menu and select the "Drive Wiper" sub-tab option.
3. 
   Select Wipe, select "Entire Drive (All data will be erased) " then Security. Determine how many passes it should take ("7 passes or 35 passes") and the drive you wish to wipe.

   1. The more passes the lower the chance your data will be recoverable. However, more passes may make the process take longer to complete.
4. 
   Select Wipe: This process can take anywhere from a few minutes to days, depending on the number of passes and free space to recover. (400GB with 7 passes took me 8 hours)