I have the “blue screen” on my hp desktop running windows xp. I have seen online, software to download that will clean the registry. How can I download if the computer is frozen on the blue screen?

Windows Vista black screen with movable cursor after welcome screen.

I've tried to solve it using recovery disk, unplug any connected cables, RAM, CMOS … cheked every thing but there is no change. Please i don't want to format my hard drive b/c i have important files on it.

Please help me figure out how to fix this! Thanks!

I'm looking for something that won't mess up my system registry like all the others I have tried before.