Need help with Program Launch in Vista

Hi! I already posted something here about it... But I need a clear and
simplified way to solve the situation.
Here's what's happening:
Everything was ok since i bought Vista. I installed various software
products, and everything was fine. Then, when I started iTunes, Vista
presented that bar of installation, like it was the first time I was opening
the program. Later it started to happening with Office 2007 and WL Mail...
So, everytime I open one of these programs I have to wait until the so
called "installation or configuration" is done... It doesn't take too long,
but it is very annoying... Please send me some easy-to-apply advices...
Thanks.