I have a 5-year-old system with a fairly new hard drive. Sometimes when the screensaver appears, after a few minutes, the screen freezen, no animation, and I get an error dialogue box says: ERROR IN GLPRO script and Subfree: Local memory block corrupted. Then I have to reboot. Whats this?

is this a standard XP screensaver or a 3rd party one? Hopefully my advice will help you...Please post back with your results as it will help others.

Third party screensaver made in the UK called Aquatica. I have had it for 5 years and no problem until now.

Strange...when I googled **ERROR IN GLPRO script** google asked me for verification numbers to proceed, saying something about a virus (So of course I exited and rebooted)...I think you should try an online scan at either housecall or Kaspersky, as they give you the options to remove the problems. Hopefully my advice will help you...Please post back with your results as it will help others.

I installed Kaspersky and tried to run the scan on 3 separate occasions. The scan took so long that my system crashed before the scans were completed. The installation was time-consuming. I got impatient with this program and removed it which also took some time.

running an online scan doesn't mean that you install their software. The only things to install are the updates. If you are adventurous you can D/L HJT and make sure to make a HJT folder on C drive and then extract the files to there. Then scan and post your results in: http://hijackthis.de/ Then google the questionable and bad results and see if they should be removed. Hopefully my advice will help you...Please post back with your results as it will help others.