Windows Live Messenger fails to sign-in from a Windows 7 machine

As I have been rolling out Windows 7 test machines in my organization I have noticed that once in a while Windows Live Messenger would refuse to sign-in. If you were to use the same account on a Windows XP machine or another Windows 7 machine it would sign-in without issue. The majority of our applications have been packaged and pushed via SMS so the install is consistent on all workstations. There seemed to be no rhyme or reason why Messenger would refuse to sign-in from some Windows 7 workstations. After much searching we found a blog post (http://dreamlayers.blogspot.com/2009/12/windows-7-cant-always-automatically.html) about an issue with Windows 7 and root certificates. It seems that some Windows 7 machines fail to update their root certificate automatically which in turn can cause Windows Messenger to fail when you try and sign-in. To resolve this issue download and install the latest root certificate update from Microsoft. (http://download.windowsupdate.com/msdownload/update/v3/static/trustedr/en/rootsupd.exe) After the update Messenger shouldn’t have any issues signing in.