Visual Studio build question

I've a general Visual Studio question..
Whenever I want to test a C/C++ program in VS.Net (I think I had the same problem with VS6 though) by pressing F5, it tells me that some project files are outdated and asks me if I want to rebuild them... so everytime I have to press F5 and then yes to test my programs.

I've looked in the Preferences and stuff to turn this thing off, or let it rebuild them by default, but without success.. is anyone else having this 'problem' and what can I do about it?

I'm running XP but I also had it way back while I was running 98 I think...
thanks for your attention guys!

I simply press F7 first...

hmm ok so it happens to everyone? I think keda told me he didn't have the 'problem', but well I never thought of this solution :P thanks CB :)