I've seen this with overheating parts more often and then the other causes follow. There's no PC details but start with the desktop cover off and see if it's clean inside and share with us if the fans are working. leave the cover off and time it again. It's usually longer till lockup.
Timing my computer it freezes after 10 minutes. The mouse is still moving around but can't exit or open/close tabs. Have to switch off at the power button. Is my processor dying?