Thunderbird is set as the default email client. Photo Manager doesn't seem to acknowledge that, however, and opens a Microsoft Office Mail Messenger window, which I have never seen before. At least, it did for awhile. Now today I tried to email a picture and received an error window that says "Send Mail failed to send message". So I guess now I have a different issue.
Uninstalled Live Messenger, but still getting the "Send Mail failed to send message" error. Not a big deal since we can upload to Photobucket, but annoying cuz our previous photo program on XP did not have this problem.