Slow Computer?

It is cloudy outside. What I can do is to stay before my computer. I didn't feel it was becoming slow, but today I found it was not so fast as before. I have has my computer for five years. During the five years, I take a good care of it because I like to see my things tidy and clean. When I have time, I arrange the files and folders in order in my computer. Also I delete some files that are not necessary. However, it still has become slow. I really don't want system crash, blue screen and error message occur to my computer. 

I know something about computer maintenance. But I don't know much about that. I know how to clean Internet cookies, Internet Explorer-URL, and Internet Explorer history. Moreover, if there are too many programs start up with the operating system, it must take long for a computer to start up. While many programs make their programs start up when you turn on your computer. Therefore many programs must be loaded when the computer comes to the login interface and of course it takes a long time. You can access the startup list and remove some programs that are not necessary or some programs that you don't use frequently. For some programs, you'd better uninstall them from the Add/Remove program.

Sometimes, the computer may run slow if viruses infect your computer. In order to protect my comptuer from being infected by viruses, I installed a piece of powerful antivirus software on my computer. It can keep my computer away from viruses, malware and spyware. I am looking for a program which can help me clean the junk files in time and defrag the disks to release more spare space. There are many such programs available on the market. It is so difficult for me to make the decision about which one to buy. Thanks to the Internet, there are still many comments about various registry cleaners. The basic function is similar. The home function of most programs is an all-in-one function. It can scan all different parts of the computer and then delete the junk files and many other problems. However, I found one program with many functions. I think it is a perfect design. The functions are comprehensive. If you don't know much computer, you can simply use the home function to optimize the whole computer. If you know much about computer, you can customize many functions. If you want to know more about that, you can visit http://www.registrymum.com/ .