QuickTime (and other programs) not viewable

I go to start Quick Time and it appears that it is starting but doesn't ever
come up. I have another program that does the same thing (Singing Coach) that
appears to start but doesn't come up. With that program if I click the icon a
second time it comes up with "Can't start a second verison of the program" as
if one is running that I can't see. I appears that with both programs they
are running but either can be seen. If I start the programs before Windows
fully loads (before Windows has loaded the firewalls etc.) they will work. I
tried all kind of settings as far as allowing these programs permission,
nothing seems to work. But are Vista verisons. I'm also running Nortons
System Works. Any idea?