i left my computer on to defrag while i went out. when i returned home i found my computer lagging a lot, so i thought there was something strange thought it was still defragging. in which i opened the program and it said only completed 5%. so i turned it off still no difference. so i restarted the comp. and it froze on "please wait while shutting down windows' screen so i restarted the comp manually, and now it's frozen on the motherboard introduction screen. I tried getting into the bios but it's frozen before i can get into it. memory says and cpu tests are ok. just duno what is wrong. Hope someone can help me. Thanks in advance!