I've no idea what that white window could be about other than a "Do 
you want to uninstall the Keyspan drivers?" dialog or from the 
Keyspan uninstaller itself. Thanks a lot for supplying a step by step 
solution for those affected!

I've moved your posting into the thread you refer to, so it's easier 
to find and put in context for those searching for it.

Best regards, 
Felix