ok so i installed power dvd and it tells me to restart so i do. Then when i log in i see power scan pop up which ive had a few times, i beleive its adware or soemthing. Anyway pc crashes then restarts with no warning..never happened before but ok. I try logging in again. Im on for like 2 seconds and it cuts me off and does the same thing. I get no error messages its just an endless cycle. Theres no way i can run any virus scanners becuase it doesnt let me in long enough. Ive heard of repairing windows but whn i attempted this it told me i would have two OS on my harddrive which is asking for trouble! So i didnt want to lose all my data on my hardrive. Please any help? im totally clueless Oh and my fan is working fine. Ive never experienced this problem before. Anything i can do without logging in to sort this out?