Replying to How to wipe the contents of your computer... (for all you techies)

Alright, so I need to wipe my comp. cause it had sex with a lot of other comps and got some stds, so it needs to be rebooted and the whole chabang. The only problem is that I've never wiped a comp before, and i need to know how to do this. By the way, the comp I need to wipe is a sony vaio, runs microsoft, and I've tried anti-virus shit, so don't tell me to clean it or anything like that. So please for all you techies, help me with this shit.