Hi guy I Just Recently Installed Service pack 2 to my windows xp. But i can not get into windows. i just get the stop c000021a. Ive tried everything and nothing works. Safe mode gets it also. Is there anything that i can do to fix this? Any help will be appreciated. Thank you in advance. Hmm I think I might have to reformat my computer. But is there a way to keep my files on my computer. I set a system restore point before i installed service pack 2.