Hold ALT and press ENTER. This triggers Window Mode/Full Screen. Fooling around with this may recenter your window.
If not, then go to your Display Settings. I'm assuming "Adjusting Screen Resolution" means re-adjusting; if not, then apply a different screen resolution, then set it back to your previous setting.
You may also want to be aware of any monitor plugs/multi graphic cards. Try changing the main monitor or main graphic card (if there's a selection), apply, then revert it back.