There are two incompatible addons in my addons list that the Uninstall button is disabled for. They were working well in Firefox 3.5, but upon installing Firefox 3.6 they became incompatible.
The first one is PC Sync 2 Synchronisation Extension:
The second one is Firefox Synchronisation Extension:
How can I uninstall them?
Best Answer
Some programs install global add-ons (available to all users of Firefox on your computer) for Firefox. Because these aren't local add-ons (installed by you for use on your Firefox profile), you can't uninstall them in the usual manner. Most global add-ons are installed either by copying the extension to C:\Program Files (x86)\Mozilla Firefox (or equivalent directory); or by making registry entries. Please read this article carefully as it provides details on how to remove global add-ons.
If your intention is to make these plugins work with FF3.6 (rather than removing them), you can disable compatibility checking.