This may seem mundane, but we are unable to make any headway on this problem with a computer we have recently obtained and upgraded to Win XP SP2. We have successfully installed Trend Micro Internet Security Suite 2008 (antivirus and anti spyware) along with System Mechanic, latest version. The latter two are working fine on two other computers in our home (no networking, all are operating as stand alone except for a common router connection to satellite broadband). The problem child is one made by Compuland with an AMD 450MHz chip, 350 MB RAM, 12 GB memory. It was screened by MS before loading SP2 and all updates and all installed ok. The crazy thing just decides to freeze up at unpredictable times, sometimes after a minute, sometimes after a few hours, there is no consistent behavior, and all that is possible is a hard boot to restart. This may prove to be something basic we are overlooking, we would greatly appreciate any suggestions, thanks a million in advance. salmon fan.

Well... for starters.. 350MB of RAM is very minimal to run XP
However, you can regain some of that by tweaking some of the services that XP runs by default.
Click on the XP services guide link in my sig--
note-- if you shut off a service and one of your favorite apps wont work-- XP will notify you that a needed service is disabled. Every PC is different, so you will have to learn what works for you

thanks for the links! I will be trying them and will follow up.