Games very small

I recently purchased a new Surface Pro before heading on deployment and downloaded a couple games from GoG.com. All of them seem to have the issue of showing in a very small window in the middle of the the screen surrounded by a large boarder of black. I have yet to figure out how to get these games to full screen such as Heroes of Might and Magic 3, Empire Earth and Age of Mythology. Any help would be greatly appreciated as there is no way I can play these games in such a tiny window. I have tried using all of the compatability windows options and none of them do the trick. Any suggestions?

is there an option inside the game to change resolution? , sometimes there is a tickbox for 'play in full screen' there too...

Yes in empire earth there was. Didn't see one in the other two which they are the reason for posting on here.

What graphics card are you using I had this problem and discovered that there was a box to check in my card resolution and screen setting.

I'm not so sure as its in the windows surface pro.

I'm having the same problem with the HMM 3 screen being small. Has anyone found a solution yet?