Full Screen programs / games won't maximize after being minimized.

The only way for me to maximize them is to go to the taskmanager and double click the program or click 'switch to'. This get's a bit annoying and sucks that I can't just alt tab back to it. The thing is, when I'm in task manager, the program is noted as "Not Responding." If it's not responding, how am I still able to maximize it through the task manager? Any ideas?

And another symptom I have is that some windowed programs (e.g., league of legends client(champion select screen)) keep on automatically refreshing themselves. Like for instance, when I'm typing in the league client, it would start rapidly refreshing or changing priorities or something, such that I can't even type a few words without having to click back to the program in the taskbar. I've tried malware scans with malwarebytes antimalware, as well as windows security essential. A few trojans and malwares came up, but none of them fixed my issue.

Sorry if this is hard to understand, it's quite difficult for me to explain. I might make a video showing my issue if you guys can't help me with a solution based off of the above.

Thanks.

bump . *not sure if there are rules against bumping on this forum. if so, please inform me, even if you don't have a solution.