Windows ME has a memory leak that shows up under cretin conditions, like running a P2P, or a full system virus scan. Xolox may not use more than 91mb at peak usage, but WinME will waste all the RAM you have (causing your system to grind to a halt) unless you have a memory defrag program.
Speaking of Defrag… I neglected to mention that a fresh defrag of your HD will free some resources and help Xolox (or any P2P) run better.