All the sudden my laptop is displaying a blue screen and an error message C0000221 bad check sum. I have searched the internet and found a couple of fixes. One fixes tells me to do a Windows repair and boot from the cd. I am able to boot from the cd when I select R for repair I get a black screen that tells me to choose which Windows I want to repair. I selected 1 and enter then it asks for my administrative password and I do not know what it is (laptop was given to me) so I hit enter and it won't do anything after that. Does anyone know how I can continue from this point with the repair? I have two final papers due tonight and I can not access the work that I have already done. Thanks