Try killing the plugin container in Windows task window. It worked for me.

No problem with procedure, but didn't solve the problem. Any other ideas ? Thanks.

Run the Firefox program once as Administrator (right-click: Run as Administrator).
If that doesn't help then do a clean reinstall.
Download a fresh copy of Firefox (http://www.mozilla.com/firefox/all.html) and do a reinstall of Firefox on top of the current version.
If that still causes the same problem then do a clean reinstall and remove the Firefox program folder.

See also:

• http://kb.mozillazine.org/Software_Update (Software Update not working properly)

Hi,

I also had this problem on Win7. Right click->Run as Administrator reolved it.

Thanks