How do I erase everything on my pc?

You can. Re-install windows. When you go to re-install, reformat the Hard drive at the same time. This will essentially do what happens at computer manufacturer plants: they install the OS for you, and leave your computer with a fresh install. You are just repeating the process.

You will need;
Screwdriver
Location of harddrive
Large pencil with a good eraser

A lot of big PC makers store a copy of of the install files on a separate partition on the hard drive. When you boot up it may say something like “press F12 for recovery mode” and then you can just reinstall everything from there. That is going to be different for every computer and it also depends on if the people who built your computer included that option.

*If your pc came with the install disks for Vista that option is probably not included. Just boot from the install CD/DVD and format the hard drive and re-install.

Add on question: I’ve been thinking of doing this. I have XP pro. If I do a reinstall, will I then have to download the zillion or so updates and upgrades, or will there be 1 update that has all the prior updates?

PS for erasing, I do not agree with skabeep. A white vinyl eraser is much better. It is less abrasive and will be less likely to scratch your disk, and remember to erase in a radial pattern.

big magnet do that good to

@jvgr

Your first update will probably be to SP3. After that you will have to update and reboot. And then you will need to do it a bunch of times to get up to date. It is a pain in the ass but it is for the best.

Magnetize some steel wool and get to scrubbing (wear rubber gloves to prevent electrical shock)

If you have a restoration disc that came with the unit, use that. Also, do not do a Quick Format when it asks you to do that.

If you want to do a secure wipe, there are a few free tools out there that you can Google for out there. I would recommend writing aeros to the hard drive 7 times. That’s generally a pretty good wipe.