How do I reformat my hard drive

I just bought a Dell Inspiron 2600 from a friend and I wanted to reload the system disk ( WinXP ),
after it loaded the disk it now tell me ” not enough resources to compleat ait” or something like that. I called Dell support and they would only tell me I needed to reformat the hard disk drive. They would not tell me how because I got it from someone else. Now my computer is a paperweight. Someone please tell me how to do the format on my laptop.