what is best way to clean all personal information off of your hard drive?

Manually deleting unwanted info & run cleanup. (free link below)

http://www.stevengould.org/software/cleanup/

Some smart people here missed where the question said WITHOUT LOSING THE OS

THE ONLY WAY is a low-level format of the Hard drive. THIS is NOT done with the format command, and WILL remove the OS. (It requires a special program that is run from a DOS boot disk!! It will ALSO take SEVERAL HOURS and must NOT be interrupted during the run!)

SO, You need a copy of the OS to reinstall, after the above.

For a less drastic solution, use a "security file delete" program, (there are several free ones that meet government DOD specifications or better!)

Uninstall ALL but the operating system and remove ALL personal files. THEN use the program to "overwrite" all "freespace" on the HD. (With some, you can delete and overwrite as a single operation!)

Even then, it is POSSIBLE that SOME information can be recovered, but not by the "average" person or shop.

Let me make one thing clear, you will never get everything off your hard drive that is personal. That is why it is very smart, important and wise to not be someplace/web sites that could get you into trouble with the law if they should ever legally confiscate your hard drive and or your computer, for what ever reason. None of us want that to happen but nothing is impossible. As an experienced computer user, operator and computer teacher I can tell you for a fact that government organizations like the FBI WILL find where you have been, no matter how many times you have erased, formatted or what ever your hard drive.

there are free programs that let you wipe the free space on your computer without messing up the OS.

To clean up specific files and the drive's free space, try Summit Computer's free Hard Disk Scrubber 2. To be extra cautious, check Heavy Scrub to write over the disk three times

http://www.summitcn.com/download.html

There are quite a few system cleaners on the market. Window Washer from Webroot is pretty good. I use it all the time.

Format and reinstall. Even if you format your hard drive it will never lose its information. What you have done on your computer will be on there forever. The government can take your hard drive and get any information they want from it no matter how many times you format.

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