So last night i was playing medevil 2 total war when all of the sudden my screen went black. I had not dropped my laptop or anything but it just was gone the computer was still running so it had not over heated but it was not on. I turned it off and left it alone over night then this morning i turned it on to a error message that i did not think to write down but some basics on it were. (something about a Ethernet,and to check connections as well as Raedon which i believe is the company that made my video card). After this i turned it off turned it back on... nothing absolutely nothing bios didn't even boot up. So walk away let it cool down again turn it back on to a different error message this one read "PCI BIOS calls not supported" this time a issue with bios then later on a different attempt to boot it i received the message "The file is possibly corrupt. The file header checksum does not match the computed checksum" I researched this message the two parts that i heard could cause this error was the RAM and the Harddrive. The most recent issue i had was it booted up actually got past BIOS but then the screen had random colors everywhere like the video card was dieing or something. In between these attempts are usually hour intervals and also some times the little - appears for BIOS loading but it just keeps blinking and does nothing. I can't tell if this is a video card error or a RAM error or a mixture of the two. Also for any additional info the computer came with Vista but about 6 months ago i upgraded to Windows 7. Any ideas would be greatly appreciated.