How can I completely clear my PC of private data?
As a Dad I'm pretty concerned about having my family's private information stolen. I'm also about to sell the family PC, which has loads of personal files on, like Excel/Word docs, saved bookmarks to my online accounts, etc. I've deleted all these, but a friend told me they aren't really gone and could be recovered with the use of some software.
What's the best way to ensure complete destruction of my hard drive's data, without chucking it on the fire?
Encryption is easier
If you're using XP and NTFS, use EFS to encrypt your disk. http://support.microsoft.com/kb/307877
Or you can use TrueCrypt for Win 2k/XP/Vista and it doesn't matter what format your disk is in: http://www.truecrypt.org/
dd is your friend
Don't bother with any of those crazy bought solutions. Simply avail yourself of a Linux bootdisk distribution (such as Tom's Root Boot for a floppy, or knoppix for a CD). After booting up the floppy/CD and logging in, type:
dd if=/dev/zero of=/dev/hda
and wait until it finishes. Replace hda with sda for SATA disks.
The contents will, in my opinion, be erased sufficiently well as to be effectively unrecoverable by most people likely to come across your old computer.
Repartition and reinstall an OS if you choose to.
i've been doing this for years, use a bulk tape de-magnetizer and zap your hard drive, then format and re-install your system files. simple and effective.
What hard drive?
Good manufacturers provide software for this, usually in bootable form.
Don't be one of these fools who sells their PC with no hard drive, throwing money away.
Disk Wiping Software
You could try one of the following software products that erase personal info from the hard drive
Paragon Disk Wiper 8.5
PCSecurityShield WinShredder 2