You mean; the game/browser window minimizes when you run it fast?
1. Do you run it in expanded window (click on top right window size icon)?
2. Or resized window with the mouse, to fill the screen?
• If 2, try pressing the ctrl key and expand the window with a click on the expand window icon, (top right) and next close it from the file menu, after it closes release the ctrl key. This will make the program remember the window size.
• If you use 1 to expand the window, the issue may be graphics issue. What GPU are you using?.
3. Keyboards can stop working from: a) BIOS is corrupted, b) virus infection, c) motherboard issues d) PSU issues.