Please stop double posting. There is an edit button.
I have seen Bad RAM and Bad video cards do this. If you take out the video card and use onboard and you can see everything, then we know video card is bad. Don't worry about getting into BIOS yet.
Taking out the video card will default it to onboard in 99.9% of motherboards. Your comptuer needs to be real old, or a low-end dell for that not to work.
Hold on...a PC that just hangs, and then won't power on...Try reseating the memory and video card. If that doesn't do, your motherboard died (BIOS). Since it's less than a year, you can contact you board manufacturer and get a replacement