I have a Sony notebook computer with Windows XP. For some reason it stopped turning on. When I hit the start button it starts up and cycles through a hard drive self- test (when the computer is not shut off properly), and when it finishes it reboots and does the same thing over and over again. I tried using a boot disk from another computer but I still can't get it started. I have some photos on it that I'm trying to save so I'm trying to avoid reformatting. I would appreciate any suggestions that anyone has. Thanks.

Can you boot up in safe mode? Try hitting F8 as the machine is starting up, hopefully you will get the option of starting up in safe mode. From there you should be able to salvage your photos once in safe mode. I had the same problem but had to reformat in the end.
Bill

Use the recovery console here - Using the Recovery Console - Helljack6.com