I was trying to install Mandrake 9.1 on my desktop when it prompted me that I needed to defreg, so i did. When I rebooted to continue install it still said I needed to defrag so i rebooted again to go into windows and uninstall more programs and defrag again when my comp came up on safe mode.Did a restore and rebooted, only now, when boots up screen comes up saying something about couldn't start virus protection, i click ok, comp goes thru boot into windows but when it gets to point I can do something, lots of vertical black and white lines come up on screen then goes blank! What in the world did I do and how can I fix this? I don't have my windows cd since this comp came preloaded (I bought it used) and I really need to keep my windows and programs w/in intact until I see if i like linux. Please help...desperation has set in!! Thanks in advance!