Not Responding is caused by a couple of things. First, the Director is doing important stuff and when Windows asked "hey, buddy, spare a nickle?" the Director was off doing its important stuff and couldn't respond quickly enough so Windows reported that it was... get this... not responding. This will usually go away and can be safely ignored. If it happens too frequently, let me know since it may indicate a problem but usually it's an overworked computer.
The second problem is antivirus. I hate releasing new versions of the Director because it takes the antivirus vendors a while to find the new version and mark it safe. Until they do, they get all uppity with the Director and get all in its grill which makes the Director get aggro back at it and eventually they have a dance fight a la "West Side Story" which sometimes ends badly. Tell your antivirus to be nice so the Director doesn't have to dance at it to get over their differences. I mean, really, it's just a petty difference, can't we all get along?