There is so much else that I'd need to know that I will not be asking for all the gory details. Instead I'm going to note that if you are running a firewall, it can eat resources this old OS can't spare. But you didn't reveal such. That's just one of a dozen issues.
Start with Optimizing Windows at http://www.aumha.org/articles.htm
No parasites allowed with scans by ADAWARE, SPYBOT SE and HOUSECALL. I will not supply links to the items since you can find them with google.com
And finally, the video driver must be current or printer output can fail. Microsoft does not update said drivers. You do that.
I am using fuly updated Millenium and the latest (V10.3) and last updated Printer Driver.
Each time I try to print a document, I get an error message indicating that the Printer Driver has caused a fault in the Printer Driver and will be closed. Sometimes I can click on ok and the error message closes and the job will print.... other times, the system will immediately restart. I have tried going back to the original driver I recieved with the printer with exactly the same results. I have tried to print with every program (except Explorer) shut down with the same results.
In trying to diagnose the problem, I have used System Information and under "Problem Devices", the printer showes up with an error 28. No clue what Error 28 is or how to get a list of errors.
Any help would be appreciated.