Windows 7: program default associations

Hello Good People of the Forums:

It's been a long time since I've had a problem that I couldn't solve myself so I'm turning to my usual source of information.

I am having a real problem getting a program default association to stick. Some background:

Some time ago I switched from Windows Live Mail to Thunderbird. I did this because WLEM would only send pictures in batches which no one on the receiving end could open. (I never could figure out how to send each photo as a separate attachment in a single e-mail) Thunderbird worked fine until my latest O/S reinstallation, (I do this twice a year when I notice little glitches in Windows 7 i.e. blank windows appearing when I reboot, strange messages informing me that files could not be found when they have been found and loaded, etc.) After reinstallation of the O/S, Thunderbird worked fine for about two days then all of a sudden any links embedded in the e-mails would not work. According to Mozilla the problem was in the default associations. Sure enough, the default association showed there was no program associated for HTML or HTM apps. I set Thunderbird as the default program but it will not stick. As soon as I close the association page it goes back to no association.

I can work around it but it is a real pain in the rump. I have Micosoft Outlook (I guess this is a new app from MS that replaces HotMail) on my favourites tab and after getting an e-mail with a link in Thunderbird I have to load Outlook and import the e-mail to activate the link.

I would appreciate any suggestions you may have.

Regards
Powell Lucas

P.S. I don't want to run a system restore because that would mean I would have to reinstall all the programs and files that installed after reinstalling the O/S.

Have you tried uninstalling FF Thunderbird and reinstalling it?

Yep, three times.

Have you checked your system for any spyware, maware and virus's? These have been known to cause such problems.

Yep, I've run two different AV programs, I've run my spyware program, my driver update program, and my program updater app and nothing shows up.

You could try using this Default File Type Associations - Restore Use the one for URL and see how you go.