For several months and updated versions, very time Thunderbird starts, I get an error message: '''Either there is no mail client or the current client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client'''. If I press OK or the X to close the window, I have to do this 18 times and then Thunderbird starts up normally. I am running windows 7 and do have Thunderbird set as the default for the programs it can open.