After Windows installed an update in the middle of the night I can't open Thunderbird and I've tried uninstalling it and reinstalling with success. It says: ''Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window.'' I've rebooted the PC, shut down the PC, ended the task and still nothing. It seem that Thunderbird didn't shut down correctly and the system still thinks that it's open and running. Anyone know how I can fix this issue? Thanks, Gregg