i am having an issue... on start-up i get a black screen with a blinking underscore, i recently purchased a new CPU Cooling fan and in putting the new CPU fan in i ruined my CPU so i replaced the CPU and the computer starts up with the black screen with a blinking underscore... also before, when my computer was starting up fine... every time i started it up it would tell me, "You May Be A Victim Of Software Counterfeiting" do to the fact that the person i got this computer from said he used a CD Key that had already been used on another computer... could it be possible that my issue is that all i need to do is buy a new windows 7 CD Key? please help