It's a dell demension 2400. It was bought April of 04, so its about a year old.  I don't really know if its still under warranty or not. I never had a problem with this computer with this situation. It was alot of things on the computer (programs), I talk to a dell support person and they told me to go to the start button and hit run and type in MSCONFIG  and to click on the startup tab and disable everything. The computer was still slow so I put in the start up disk in the computer and everything went find until I rebooted the computer again and it goes to the dell load start up screen then it goes blank and black and nothing happens. This computer does not have a floopy disk installed either. I have ran diagnostics and it hasn't made any difference.