If I click on a mailto: link in any browser I receive a message "could not perform this operation ....  Mail Client is not properly installed".  If then I click OK about 50 Windows of Internet Explorer open and it locks up.  Restart fixes it.

I don't know when this started because I rarely click on a mailto: link in a browser.

Windows 7 x 32, IE10, Windows Live Mail Version 2011 (Build 15.4.3555.0308) (default), Thunderbird, Microsoft Security Essentials, Malwarebytes.

I have tried the following:

Reset Windows Live Mail to all defaults

Repaired Windows Live Mail

Set Thunderbird to default (still get the error)

Set Windows Live Mail to all defaults again

Reset Internet Explorer 10