How do you Reboot a comp? need help

i want to reboot my computer to factory default settings like all the way to were i barely bought it can some one tell me how to do that or if it is possible? because i want to remove all my virus's and all crap i dont need anymore. Please make a guide, vid tut, anything that can help me

Hello,

What is the brand of your computer?

i apologize but that intro had several vocab issues rebooting a computer is more commonly known as restarting, i beleive you meant restore default factory settings. the only thing on a comouter that can be restored to factory settings(i beleive) is BIOS (dont touch(unless instructed to)) . what you are talking about is probably your operating system which doesnt just get reset to factory settings but i will leave this to the professionals
sincerely,
seth

Dell dimension E520

Hello,

Please take a look at the instructions here:

http://www.geekpolice.net/tutorials-guides-f13/dell-system-recovery-partition-hotkey-instructions-dell-pc-restore-t7661.htm