ER_KRNLCRASH_LOG System Error 1003

My XP SP3 computer crashed about a month and a half ago and I had to get it repaired at a local shop. They reinstalled windows and were able to retrieve my data. Then 3 weeks later it crashed again. This time I installed a new hard drive and have had it back for a week now. I also have added a new external hard drive for backups. The first time it crashed I had a system 32 error and the computer would not boot at all. The 2nd time it got to the initial boot screen and would start the process of loading but would stop in a couple seconds and go back to the boot screen. I figured my hard drive was failing.

Today I used Syncback to backup but there was a failure for some reason. I then decided to try the XP built in back up program. I chose to backup my documents to my external hard drive. It started the process and then suddenly my computer screen went black and the computer rebooted.

When it came back up it said a serious error occurred although it could not tell me why. An MS web site came up:

http://wer.microsoft.com/responses/Response.aspx/10/en-...

I then checked the system log and it reported ER_KRNLCRASH_LOG System error 1003.

Any comments on what may have caused this error? With all the work and trouble I have had the past month and a half, I do not need any more! My hard drive is new and windows was just reinstalled. No viruses or spyware. I wonder if any of my other hardware may be failing? The computer is 4 1/2 years old.

Hopefully this is a one time deal. Any help would be appreciated. Thanks!