HP P6320y Will Not Boot Up

Bought new desktop HP Pavillion p6320y PC using Windows 7 and Kaspersky antivirus Feburary 2010 and it is rarely used, maybe one session every several months? Yesterday I was going to use the desktop but when I went in the office the screen was blue and said to restart computer to avoid damage. I could not get the keyboard or mouse to work so I turned it off by the power button, waited a few minutes and then turned it back on. This did not help so I disconnected power source and let it sit over night. Tried again today and no luck. The power button and fans come on but nothing else gets power. The monitor says "No Connection" and the mouse and keyboard will not light up. I have checked all cords and everything is correct, cleaned out the small amount of dust, tried another monitor and cord. This computer has barely been used at all, I have no idea what is going on??