I to have the same problem. I have a Dell E510 with media center. I was on line when it locked up. ctl. alt. del.

would not even work to get out of it so I held in the on button. After I when I tried to turn it on it locks up sometimes on the window screen, a black screen, and sometimes my desktop. since then I replaced the battery, pulled out the ram and tried each one by its self and nothing. I now cant even start it up in any kind of safe mode. I have alot of pics i need to get off my HD because I think I have no other option but to reformat my HD. My computer is only 2 years old. I bulit a computer before and it lasted a lot longer than this dell. Now dell wants me to pay $50 some dollars to help me trouble shoot it. My sons xbox also runs thru this for xbox live and now he is getting mad at dell. He will be going to college soon and he is thinking about not getting a dell now. can someone help me. thanks 

If you take you hd out of you computer and hook it up as a slave to another you can get all the files off the drive if you want. with out formatting it first.