Today Messenger stopped working. It hangs on start up. Right when it pops up the toast saying "You're signed into 2 places" and becomes unusable at that point.

Using Procmon I see that msnmsgr is spinning on

10:58:45.2355930 AM msnmsgr.exe 4932 RegOpenKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_CLASSES\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} NAME NOT FOUND Desired Access: Read
10:58:45.2356184 AM msnmsgr.exe 4932 RegOpenKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} SUCCESS Desired Access: Read
10:58:45.2356492 AM msnmsgr.exe 4932 RegSetInfoKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} SUCCESS KeySetInformationClass: KeySetHandleTagsInformation, Length: 0
10:58:45.2356631 AM msnmsgr.exe 4932 RegQueryKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} SUCCESS Query: Name
10:58:45.2356787 AM msnmsgr.exe 4932 RegQueryKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} SUCCESS Query: HandleTags, HandleTags: 0x401
10:58:45.2357029 AM msnmsgr.exe 4932 RegOpenKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_Classes\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B}\ProgID NAME NOT FOUND Desired Access: Read
10:58:45.2357209 AM msnmsgr.exe 4932 RegQueryKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} SUCCESS Query: HandleTags, HandleTags: 0x401
10:58:45.2357357 AM msnmsgr.exe 4932 RegOpenKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B}\ProgID NAME NOT FOUND Desired Access: Read
10:58:45.2357521 AM msnmsgr.exe 4932 RegCloseKey HKCR\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} SUCCESS 
10:58:45.2358484 AM msnmsgr.exe 4932 RegQueryKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_CLASSES SUCCESS Query: Name
10:58:45.2358644 AM msnmsgr.exe 4932 RegQueryKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_CLASSES SUCCESS Query: HandleTags, HandleTags: 0x1
10:58:45.2358800 AM msnmsgr.exe 4932 RegQueryKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_CLASSES SUCCESS Query: HandleTags, HandleTags: 0x1
10:58:45.2358923 AM msnmsgr.exe 4932 RegQueryKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_CLASSES SUCCESS Query: Name
10:58:45.2359104 AM msnmsgr.exe 4932 RegOpenKey HKU\S-1-5-21-2795235799-995318530-3541920291-1003_CLASSES\Wow6432Node\CLSID\{3050F391-98B5-11CF-BB82-00AA00BDCE0B} NAME NOT FOUND Desired Access: Read