Hello Alloztome, also check to set the do not run Firefox as Administrator, in the firefox.exe program in Firefox program directory.

also, version 40.0.2 (the latest) is out, Update Firefox to the latest version

thank you

Thanks for the suggestion- I do not run Firefox as admin. Firefox is supposed to update automatically but it doesn't seem to, last night I updated it manually, no difference.

Try to run the Firefox program once as Administrator (right-click: Run as Administrator).

Check that Firefox isn't set to run as Administrator.

Right-click the Firefox desktop shortcut and choose "Properties". Make sure that all items are deselected in the "Compatibility" tab of the Properties window.

• Privilege Level: "Run this program as Administrator" should not be selected
• "Run this program in compatibility mode for:" should not be selected

Also check the Properties of the firefox.exe program in the Firefox program folder.

I do not now nor have I ever run Firefox as Admin, everything is deselected in Properties/Compatibility. The problem began after I installed updates for CCleaner. I have since uninstalled and reinstalled the program. I am going to uninstall it completely to see what happens.

There still seems to be a program that is running as administrator because otherwise windows wouldn't show the UAC dialog, so proceed with caution.

Make sure to delete the current Firefox program folder before trying to reinstall Firefox.

You may also want to uninstall and reinstall the background maintenance service.

• https://support.mozilla.org/kb/what-mozilla-maintenance-service

You can check in "Windows Control Panel > Programs" for recently installed programs. I don't know if you can check for recent updates.

• Control Panel > Programs > Programs and Features > Uninstall or change a program
• Click the Installed column to sort by this heading