Desktop Operating Systems and Recovery

I was just vibin ya know until one day my pc nae naed itself to death and its hard drive went 6 feet under and died i replaced it but lost some screws and couldnt get screen completely on and then while i was playing a game my cat breaks the screen (i use a monitor instead of its screen so it just hangs there) basically he walked on it until it broke off without me realizing and then he comes to my keyboard while waiting for game to load presses sleep mode now wont come back on. I also got rid of the screen mayne not the smartest idea and whenever i plug it in the light to show its one flashes 7 times then repeats ive tried alot od stuff and ive tried to do stuff with keyboard, tried to reset or sum stuff like that. But ima need some help. Sum serious **bleep** finna happen in my game in a week, and this game only available to pc only.