I started up my computer as normal, and clicked on my username, I expected the log-in box to appear, but after 10 minutes nothing happens.
So I got my other spare computer and searched up the problem, I found out that I had to boot into safe mode and use system restore to restore the problem. It worked, a week later the same thing happened, I fixed it the same way. This time it happened again, I tried to fix it the same way but nothing changed, I tried the same thing again, nothing happened.
So now I don't know what to do. I was thinking of re-installing windows 7 pro, but I thought that there must be another way to solve the problem. By the way, every time it happened, it occurred just after my PC installed and optimized windows updates. So it probably has something to do with this or the registry.