Hey.

When I start the game it goes fullscreen then after 1-2 seconds it jumps back to a small screen. Do i have some setting wrong?

Have windows 7. 32bit

Telling us which game could help a bit ;)

Sorry.
All of the games in the MM1-6 pack.

Edit: Well... the games which uses dosbox

Which card do you have? That sounds like some automatic setting in ATI CCC or NVidia Control Panel regarding scaling.

But it doesn't switch to windowed mode, right? Just the screen gets smaller / black bars appear?

Geforce 9400
It switchs to windowed mode.

Since it happens with DOSBox games, try using different graphic modes. (there should be config setup in Menu Start->GOG.com->[game folder] )

That did work. Thought I tried that before :-)

Now its just MM6 that I notice got some error.
DDraw->SetDisplayMode() failed

Do you have latest DirectX 9 installed (it doesn't come by default with Vista / win7 )?

Regardless, go to Menu Start->Run->dxdiag-> 'display' tab and see if DD acceleration is enabled.

To Fix Intel Scaling Glitch.

#1. Right Click on Desktop & Choose Screen Resolution. And Change resolution to 1024x768.

#2. Goto Ctrl Panel Click on Intel Graphics & Media. Scaling Option will now be avalible, Select Stretch to Full Screen and Save.

#3. Again Right Click on Desktop. And change your Resolution back to Native Resolution, Click on Accept... Now you should be set for Full screen Graphics in Games.