I finally found some time to set up the old Micron computer, which also had the
Remote Desktop post SP2 problem, but with the RC2 of SP2, which I had uninstalled back in July. So, I put on the real SP2 for XP on that system and, as I assumed, Remote Desktop no longer worked afterwards. I tried to install
the hotfix that Microsoft support let me download, but (not surprising, given the dates of the files) it wouldn't install, saying it was for XP SP1.
I have decided I have no more interest in trying to figure this out, because I honestly don't think there is anyway to solve it, without wiping the system and re-installing XP from scratch, just as I did on my AlienWare box a couple weeks ago now.
I feel for the others out there with this problem. It is rare and I sure wish I knew what commonality I had on my AlienWare computer and my older Micron, which had no similar hardware (other than both using a VIA-based motherboard.) If there is some configuration setting, tweak, or app that I installed to cause this, then why haven't my subsequent SP2 installs on various laptops and desktops not had this same problem? Since I know that I'm not the only one having this problem, what rare commonality did our problematic XP systems share? Oh, the mysteries of Windows.