How to stop games from being minimized on its own every so often during use?

When I launch a game from any launcher battle.net, steam, etc. the game minimizes every few miutes or so even just sitting on the main menu. It happens when I'm right about to do something at a difficult part or when I have to shoot to survive or run away. Like it happens so that I die or miss. Like you can't really get into the game/match/level and like it waits tilla good part because it can't happen that often or it doesn't seem like an issue, i also reinstalled windows from scratch and regretted it because the OEM flash was pretty solid, the computer felt different and I didn't know what it was. I tried to minimize black ops once in steam by hitting the windows button just to check something and it wouldn't let me pop-up windows task bar etc. and when doing control alt delete to hit the task manager it doesn't let me close the game, if it freezes or won't let the task manager come up I hit lock, then log in, if it still doesn't work I do it again and hit sign out then it lets me log in to the desktop with game closed, and then now it minimizes every few minute or ten or twenty like in battle net call of duty online matches. I haven't had this issue from rockstar.