My LAPTOP KEEPS RESTARTING?

Hi, I just bought a laptop brand new 4 days ago, it is a
Hp Compaq Presario V3000

a couple days in, I believe a virus went on it, and now whenever I On my Laptop it comes up with the screen

Choose start windows normally
safe mode
safe mode with networking
safe mode with command prompt
and ect



When I pick any of them the same thing happens... the windows xp screen pops up and then it restarts and follows the same cycle!
PS I DONT HAVE ANYTHING IMPORTANT ON MY LAPTOP SO WIPING OUT EVERYTHING IS AN OPTION
PLEASE SOMEONE HELP ME!!

Any ideas! please im am really greatfull to anyone who can help me with this problem and THANKYOU for taking your time to post a response