Main Message Window not closing on Windows restart

[dbminter]

Nearly every time I restart Windows, I get a dialog from Windows saying something called Main Message Window doesn't close.  I have manually choose to cancel it from memory.  I was wondering how I can begin to track down what this Main Message Window might be from?    I don't know anything about checking Windows system logs, etc. so I'll need some hand holding.    What would I use to check for logs that might contain a reference to something that didn't close properly on Windows restart?

[dbminter]

I think I might have discovered the culprit.  Acting on a hunch, I uninstalled nVidia's GeForce Experience.  I can always manually check for updates to my graphics card from their website.  That application never worked right right out of the box on my new Dell system.  For many revisions, if you had ZoneAlarm installed, it simply didn't work at all, even if you added rules for it.  nVidia finally fixed that but the application still never worked right 50% of the time.  Checking for updates would sometimes never resolve.  Refreshing the games list would sometimes never refresh, etc.  application was more trouble than it was worth.