What should I do to my computer before i donate it?

First of all, good on you for donating those old computers to charity, and good on you again for making sure they’re clean and ready for use when your recipient gets them. Thankfully, getting them ship-shape for donation is quick and easy, and it won’t take much work to ensure all of your data is off of them before you drop them off. Best of all, this advice is applicable regardless of your reasons for disposing of a computer. Here’s what to do:
Step Zero: Back Up Everything
It goes without saying, but before going through with anything else here, make sure all of your personal data is backed up from all of the computers you’re planning to donate. You don’t want to get halfway through the rest of this only to realize that one of those drives may have something important on them. If you haven’t already, back up all of the computers you’re going to donate. If you’re not sure how, check out our guide to backing up your computer.
ref: https://lifehacker.com/5835369/how-do-i-securely-wipe-a-computer-before-donating-it-to-charity
Code Warrior and Software Ninja; Blogger extremist and all around good guy