I want to wipe my computer clean before I get rid of it! I don't want anyone to be able to pull up any old files! It's one of our business computers and we have personal info on it! Please help!

Well to wipe it 100% + clean they recommend pulling the hard drive and running it over with a truck- You might want to try this instead -- Savage
Darik's Boot and Nuke (Hard Drive Disk Wipe)

Hehe thanks!

Failing that mulitple formats works a treat too.
Doing the opposite to what it is already.

Eg
Starts as NTFS > Format FAT32 > Format NTFS > Format FAT32 > Format and rebuild NTFS.
Could always throw in a Linux format for good luck.

I challenage you to get data off that ;)

Yep, all the above is good advice.
But if it's a business machine, I would physically destroy the hard-drive to be on the safe side. Just hammer a 6 inch nail through it and that will make it safe.

Hard drives these days are amazingly cheap anyway (£40 for a 250gb drive!)

Great thanks!