xp sp2 start up problem

[misio]

Hi Newbie here, basic skills. Turning on what has been a very stabe system for 5 years it runs for a few seconds, fans on, black screen, as soon as the two cd drive lights start to flash, fans go off for a second or two and then the whole thing recycles. I noticed recently that on start up the screen was Ok then would disappear and come back of its own accord a few times before it settled down. Mouse cursor was sticky jerly for a while too. I managed to get it to boot this morning only by continually pressing the restart button on the tower. It eventually booted. No new hardware or software installed recently. I'm now worried about ever turning it off! Running AVG free. Most recently ran AML free reg cleaner reg, where i noticed it had a problem with MS silverlight errors but that's all. Please be gentle with me. If this is a hardware problem the most I've ever done is change a case fan. Thanks to anyone who can give me any guidance.

[Bob_180_Bob]

As you may not be able to start it again you will need a boot disk to help you, go to UBCD site, download the program used to make an Ultimate Boot CD.
1. Run the program and make a Boot CD from the ISO.
2. Use that CD to boot your faulty computer.
3. Before you run any other program in UBCD, I recommend that you run a virus scan and malwarebytes to remove all viruses that hide or can not be removed when Windows is running.
An Ultimate Boot CD for Windows is a bootable recovery CD that contains software used for repairing, restoring, or diagnosing almost any computer problem. Use the link below to download a customized ISO file of the Ultimate Boot CD for Windows. A CD-ROM created from this ISO file will be a bootable disk containing a myriad of diagnostics and utilities. The software contained on the Ultimate Boot CD for Windows is either freeware or has been designed "for personal use only". Check the site for all the different software that is included on the CD and if necessary, instructions on how to use that software. Assuming there is no hardware problem with your computer, you will be able to go on-line and update any program or locate other software (drivers etc)
Click here for the official Ultimate Boot CD for Windows website: http://www.ubcd4win.com/
If you don’t know how to burn a CD with an ISO file, check the site, there detailed instructions on using different burning programs.

[misio]

Bob Many thanks for your assistance. I have created my UBCD, which has given me some comfort, however where to go from here? Would it be a good idea before switching off my computer to go back to a previous restore point and see if that works. If not what would you suggest?