Unable to get the OS starting on screen

Hello,

I have assembled a comp with Core 2 duo 2.93 GHz, ASUS Motherboard with 2 db ram, 1 gb intel grapcs card, 320 GB hDD. No floppy drive and have DVD drive.


I facing issue with this comp. recently it was working fine. Recently got attacked by a Virus. Till that time OS was working fine. Tryed to Format the cmp with XP Pro bootable disk and when pressed a key to boot from CD after that nothing happens. Tryed with a diff disk still same. Took out the disk restarted the comp, now it shows the image of Asus motherboard image shows its started as it shows all other options but doesnt shows any idenfication of OS. Restored the BIOS to default settings. Now not able to format the comp.

Please help me with it as its like this from one month