USF4 crashes and won't close (PC)

Hi,

USF4 works, but randomly seems to just stop responding and needs closing. But after I close it, it stays open in processes and just WON'T BE ENDED. So I can't close steam, and can't even restart my computer without holding down the power button as the process just WON'T BE CLOSED. I've literally just updated my nvidia gpu drivers and will be trying again soon, but I'm not keeping my hopes up. Anyone know what I can do to fix this?

Thanks.
-DreadAlert