You don't need to wipe bios. It's pretty hard (almost imposible actually) to get to the level of bios with a virus. Just backup the data you want to keep, get a windows installation dvd, start the installation process (by booting through the dvd), select clean install, select your hdd, next, next, wait for it to install, it will restart automatically and you can configure the first settings there. The installation process will format your hard drive, effectively deleting everything on it. So backup any data you need before you start it cause you'll lose it if you don't