Hi,
thank you for your answer, though I must disagree: games aren't crashing. As I said, full-screen games MINIMISE to desktop, they don't CTD. I can resume playing after I click on their icon in the taskbar, sometimes as long as three hours after. Full-screen games minimise and windows are deactivated (games, file explorer, sometimes even web browsers). This happens after 2 minutes I run either of these, once per boot-up. Sometimes it can go unnoticed because of regular clicking the active window or program but is noticeable, annoyingly so, when I believe I'm writing and then I realise I'm not. My guess is that some other Windows' program is interfering. Sometimes it occured right before a McAfee notification popped up. But I uninstalled it and it keeps happening.
I hope this explains the problem better