restarting Windows XP

From: confused 1 (1_at_discussions.microsoft.com)
Date: 07/31/04 

Date: Fri, 30 Jul 2004 23:21:01 -0700

The computer has been attacked by a virus. I ran Norton anti-virus. It was able to detect Bloodhood packed. I couldnt delete it for a while..started by deleting Temp internet files...the problem is that I just want to start all over from scratch. How do I go about getting rid of everything and starting from scratch where I need to install Windows XP over again?