I want to donate it, but I don't want any justification numbers, passwords, or any other personal info getting out within.
Answers: Reformat the HD if you want to insure against laypersons from access infirm files and personal notes. Unfortunately near are race and applications out at hand that can sift through a firm drive even after it have be 'erased'. But, it is usually not cost updated to be in motion after a couple of passwords on a elementary home PC.
If you want to guarantee the notes is gone, you can try Darik's Boot and Nuke beforehand running the seizure compact disc. It will wipe everything bad of the drive. It's possible, even after running the rescue disc that some background is still on the drive. The average party wouldn't know it's at hand and wouldn't know how to access it. However, best practice is to not set off any destiny (better nontoxic than sorry, as they say).
Darik's Boot and Nuke available here:
http://dban.sourceforge.net/
You download the disc logo and burn it to a blank compact disc. Then put the disk contained by the computer and reboot it. The computer will boot from the disc and allow you to run the wipe.
If you are donating it, you should a moment ago reformat and re-partition the drive. This will erase everything. There are even excellent free programs that will erase it so that nil can be retrieved from it. Using repossession disk will restore the failure to pay files and settings on the system, but not necessarily engineer delete files irretrievable beside the right software.