> Thought that I might take a look at WLPG. Note that I only run XP,
> which appears to have its own version.

version 2011 of WLPG doesn't run on XP. This version has some major enhancements, notably the ribbon interface and the automatic biometric-based face recognition.

>
> My biggest problem is that fact that having installed and tried WLPG, I
> ran up Picasa3 again to compare something.... and it blue screened.
> Since then, I have been unable to run Picasa3 successfully. It starts,
> brings up its main screen, does the rescan for new images (probably 15
> seconds) and then blue screens.
> This may be coincidence, but the timing does suggest that the
> installation of WLPG is the cause.

I had similar issues with Picasa in the past, before I ever installed WLPG. But that doesn't mean WLPG is not the cause of your trouble in this case.

> - wanted to uninstall WLPG, but cannot find an uninstaller for it
> it may be part of Windows Live Essentials, since running repair seems
> to list WLPG as it does its repair (but didn't fix the problem.

I believe you have to uninstall Live Essentieals suite altogether. It might not hurt to try.

> of having to restore my mail archive if it removes Windows Live Mail at
> the same time).

Windows Live Mail is not the best email, IMHO, for that very specific reason of archive management and backup/restore. Yet, you may find a way to backup and restore your archives if you look on the Internet.