Thank you. It looks as though the time is right to upgrade from XP to Windows 7.
Footnote: I have upgraded two PCs "directly" from XP to Windows 7, using LapLink's "PC Mover Upgrade Assistant". MA3 was working fine before the upgrade, and works fine after the upgrade. Of course, I have no idea whether the files are in the right place, or the Registry entries are correct - I'll probably find out when the next installer version of MA3 comes out.
Footnote2: If you're considering that, consider buying the download version from Amazon. It's cheaper than getting it from LapLink.
Footnote3: YMMV - I didn't have problems with it, but others have.