Well... I'm posting an update to my situation, in case anyone can benefit from hearing about my experience.
After about four weeks of playing hide-and-seek with a persistent "MSGSRV32 Not Responding" problem that was knocking out my Wireless USB adapter, and trying all the various suggestions (thank you, all) from fabulous folks here, I *finally* found out what my problem was -- a serious trojan infection.
It was an infection that was not detected by the free online trojan scan utility at trojanscan.org. I actually had to download the shareware program, tauscan from Agnitum and run the advanced "deep" scan. It took 23 hours(!), but the software found 51 infected files.
Unfortunately, although I was able to delete most of the infected files, some were critical OS and application files. I finally ended up having to reformat the hard drive and install Windows ME from scratch.
Besides all the time spent hunting down this problem, the thing that really frosts me is that I thought I was totally protected from such things! I use Ad-Aware for my anti-spyware protection (which seems to work quite well *and* which I keep updated) AND McAfee anti-virus, which I keep constantly updated. In fact, my McAfee is configured to do automatic updates... which it does at least eight to ten times a week!
Needless to say, when my "yearly subscription" with McAfee is up in September, I will not be renewing. Instead, I have downloaded the free AVG anti-virus program from Grisoft (thanks to recommendations from folks here) and will probably upgrade to the paid version.
Thanks, again, to all the kind and wonderful folks here who gave me all sorts of suggestions and tips. I would have torn all my hair out weeks ago if I hadn't this forum!