User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 Build Identifier: All 3.x.x Versions up to 3.6.3, maybe earlier too Sometimes I ( and other people in discussion boards, too) have a problem with Mozilla Updates, especially FF in windows: After starting of FF it tells that an update has to be installed. If you click "OK", this ends up with the message, that it was not possible to be installed (because user has no rights for writing into the program directory). This loop never ends. If the user starts FF as an admin user, this message does not appear, or, if it does, he can perform the update without error (of course). Returning to his user account, the loop starts again - in spite of the update, that was performed meanwhile! Help to this problem is, to delete a directory in his own windows profile, that stores update information of FF. For example on vista it is in the app-data path: c:\users\<username>\appdata\local\mozilla\firefox\mozilla firefox\ There you can find the two xml files: active-update.xml updates.xml and a folder "updates" with a sub-folder "0". Both are normally empty (if no updates are present). As the program folder of mozilla is installed for all users in common, the information about updates should be stored in a central place, too and not in the windows profile of each user - especially not in the profile of a user, who has no admin privileges. I am not sure, if FF itself choses the appdata folder of the user, or if windows does that, because FF tries to write into the write-protected program folder. But, whatever the reason is, FF should take care not to write this info into a user's profile of windows. This information should be saved at place that is accessable by every user. Finding the update information at a central place, the update programm of FF would not run into the loop anymore, if a user had installed FF as admin meanwhile. Reproducible: Always I know, that Windows XP and Vista are affected, but I expect, that other windows versions deal with the same problem.

I think this is Firefox-specific, not Core.