[SOLVED] Computer gets stuck on a Black screen with a white cursor before login?

My computer was turning off every time i tried to turn it on. I ran my computer in safe mode and tried to restore to before the previous update. The computer then attempted to reboot as a process of the system restore. As it was turning back on the computer shut down again mid-process. After some research i concluded that the problem was that my CPU was overheating. I purchased thermal composite and applied it as instructed on the suppliers website. I attempted to reboot my computer but after the green-bars loading screen the computer screen became black with the cursor in the middle of the screen. I am sure this is due to the sudden shut down during the restoration process. I have tried running my computer in safe mode but i get the same result. After further research i tried the F8 advanced boot screen. The "Repair my Computer" option is not available.

I built this computer a year ago. I believe Windows is corrupted because at the start up loading screen with the small green bars the logo doesnt show on top.

Please help