How do you delete everything in your computer and reformat it like when it was new?

Answer 1

if your computer has a recovery partition on the hard drive, when you boot it up you will see something like....to start recovery press f 12..... if you have discs, put in the operating system disc and reboot from the cd. follow the prompts untill you get to the part about the primary ntfs partition. you want to delete it. then reboot and create a new ntfs partition. after formating, always boot from the hard drive. follow the prompts until finished

Answer 2

Either reinstall OS and choose New Install, and format drive then.

Or get something like Ultimate Boot CD and do low level format.