Can I use CCleaner to securely delete user files?

I want to decommission an old computer: I want to securely delete all user data from the disk. Can I use CCleaner for this purpose? I have downloaded the program and I can see that it will securely delete temp files, cookies, recycle bin, etc. I'm guessing that I should delete the user files and leave them in the recycle bin, then let CCleaner delete the recycle bin with the Secure file deletion option set. Will that do what I intend? Also, what about files already deleted, before I got CCleaner? Can CCleaner securely erase them from the disk? If not, can you suggest some products which will?

CCleaner isn't going to remove everything for wiping a system clean of all user data. If you're thinking of selling your computer:

  • If you want to literally kill all user data on the hard disk, wiping it completely clean look into DBAN.

    Note:

    If you have a second hard disk, you should unplug it as DBAN looks for all hard disks connected to the system! You’ll have to reinstall Windows afterwards!

  • If you do not want to reinstall Windows try Eraser Portable.

I like Eraser Portable.

It will be handy.

Thanks for the suggestions - I will try Eraser.