Another reason is that when you are working some program and some files on your computer and then suddenly, there is brownout or the power supply will suddenly out, there are possibility that your computer hard disk will become crash and you may have some trouble opening some programs on your computer.

My only tips when you are experiencing this problem is by using some software like Registry Cleaner, which help your computer registry to be clean and it will help your personal computer performance. But be still careful when downloading some free registry cleaner software because some of the free downloadable software have some virus in it. I recommend that you should buy on some trusted company.