I have a strange problem since I replaced my old GTX 570 with a new GTX 960 graphic card. Now Skyrim gets regularly minimized down to the bar at the bottom again and again after half an hour in average. The same happens f.e. with Attila:Total War but not with other applications, f.e. a render program. While the Total War games can be easily maximized again to full screen (so it's a minor annoyance) Skyrim usually is very unstable then and needs a lot of time till it is up again, if it does not crash anyway.

Has anybody similar problems? Maybe the drivers of the new card cannot handle the old game Skyrim? But Attila:Total War is relatively new. Is there a possible solution? I have a Windows 7 Pro system btw.

Not the drivers unless you don't have the latest - I'm running the same card on a new rig and never have had that problem. I have win10 pro instead of 7. The guys who actually know stuff like this will want to see a complete dxdiag:

If you can't get the forum to let you post with the spoiler tags, save the info to a text file, and put it in dropbox or google docs or something like that.

Most likely some background application wanting attention..... Did you install the GeForce Experience app as well when you updated your drivers? If so, uninstall it, see if anything changes. Knowing what other stuff starts with windows would be helpful as well.

What happens with a clean boot: http://www.thewindowsclub.com/what-is-clean-boot-state-in-windows