How do I wipe business computer clean of data?

I own a small business. We have about six Windows XP Pro PCs that we are donating to charity. We'd like to wipe them clean of user accounts and data first. What do you recommend that's cheap and easy? Also, how do we remove these computers from our network domain so that they don't cause issues later for the non-profit?How do I wipe business computer clean of data?
The safest method is to remove the hard drives and destroy them. Since this isn't practical in most cases, you'll look to wipe the drives clean. Take a look at DBAN to run multiple passes over the disk in order to greatly reduce any chance of file recovery.





If you are donating to a known non-profit, ask them if they plan to do their own image installation on the computers. If they are, deliver the PCs to them without the OS installed (just pass the Windows CD Keys, recovery disk, etc...). If they don't intend to install their own custom image on the computer, use the recovery media to get the computer to a from factory state.





** Edit **


rsn4ke - Even though the charity may not attempt to do a file recovery, you have to keep in mind what will happen to the system after the charity is done with it. Will it be sold off? Will they give it to someone who works with the charity? Will it be stolen from the charity? Etc... Applying a good practice to data privacy is always a good idea.How do I wipe business computer clean of data?
Find out who the manufacture of the hard drive is (western digital, maxtor, seagate, ibm, etc) - then just go to their website - under their support section you should be able to find a zero fill format utility... Find it and use it.. What it does is it formats the hard drive and it fills EVERY sector with a 0... This not only wipes data from every sector but OVER WRITES the sector, putting a 0 there... It will probably take a while to run so let it run overnight...
You only need to reinstall win (and format all HDDs during the proces) I dont think that the charity people are gonna run some recovery software in there just to get your old documents.
It's important to ensure the charity is going to sell your donated computer to a company the offers certified data destruction or shredding of hard drives. I know All Green Waste Management offers to guarantee data destruction and they shred all of the hard drives that they receive even if it is not requested. Many charities work with them. I'm sure you can find a list of their charities on their website. They recycle computers, monitors, TVs, Cell phones, and just about any other electronic recycling you need. Check them out at www.allgreenwastemanagement.com