First of I want to notice that I'm aware that there are a lot of threads on this particular subject, both on intel's and other forums. But I thought it would be a good idea to put all the information I've gathered in the past few days in one thread.
So let's start with the description of my problem. As the title says it's a scaling issue, whenever I change the resolution of a game to non-native I just get a centered screen with black borders around it. This happens with the HD 4400 chip in combination with the Nvidia GT 730M running on windows 8.1. And ofcourse all the drivers are up to date.
Now I have found out myself that this problem is related to DirectX 11, for this only happens in applications that use that version of DirectX. The best example for this is crysis 2, I changed my resolution to 1280 by 720 and boom there were the familiar black borders. But when I disable the use of DirectX 11 in the graphics option of crysis 2 it suddenly scales properly.
But this problem only occurs when running the desktop in native resolution (1920 by 1080). When I change the resolution to ANY other one, I suddenly get more display scaling options available in the Intel HD Graphics Control Panel, I can now choose "Scale Full Screen". When running the desktop at a lower resolution with that scaling option, I can run DirectX 11 games in any resolution and they will scale just fine!
For some people this works as a fix though:
1) change display resolution to below-native, 1024 by 768 for instance
2)choose "Scale Full Screen" and save
3)change display resolution back to native
But sadly for me this doesn't work, the intel settings just go back to "Maintain Display Scaling" and my games still have black borders around the edges.
So right now the fix is change desktop resolution for gaming or disable DirectX 11 when possible. I hope that the intel team can figure something out for their next drivers or that there are people on this forum that know an actual good fix. The only thing that I haven't tried yet is to install older drivers and see if those work or to disable the intel hd 4400 chip (which isn't a very good idea I believe)