Unable to upgrade to Firefox 6
I am unable to upgrade to Firefox 6. After clicking "Apply Update" from the Help->"About Firefox" window, the new update is downloaded and I'm asked to restart the browser. When I restart the browser it says "The update could not be installed. Please make sure that no other instances of Firefox is running and retry". I have verified from the Task Manager that no other version of FF is running. Even restarting my Windows OS did not help. Facing exactly similar problem while trying to update to Thunderbird 6.
Opaite Mbohovái (1)
I have found a workaround for this problem:
Downloaded FF6 directly from mozilla.org and installed it at the same location where FF5 was previously installed on my computer. Aforementioned error message did not crop up this way.
However that still does not answer why I was getting the error while trying to upgrade in the usual way.