Dave called after installing Microsoft Windows XP, and the issue of memory limits arose…
Before you go to the website I’m about to mention, you may want to lower the volume on your speakers: I was greatly annoyed by an advertisement on this site that had sound. The best “plain English” answer I found was at the “Dan’s Data” website:
“…you shouldn’t install more than 3Gb if you’re not running a 64-bit operating system.
“…a plain PC running a 32-bit operating system…shouldn’t have more than 3Gb of RAM…
“If you install 4Gb, there is no way to make all of the RAM between 3Gb and 4Gb available without installing a 64-bit OS, which you can’t do unless you have a 64-bit CPU. And even then it won’t necessarily work.”
Physical Memory Limits: Windows Vista
Physical Memory Limits: Windows XP