Computer freezing is another problem that might require reboot computer. Many times we over load the
computer by installing and running too many programs which fight for too few computer resources and a slow computer results. Or we remove several programs or games that we no longer need or want which corrupts the registry. If your computer is still running there are several things you should do to help try and maintain the operating system. The first thing would be clean the registry, then defrag the hard drive, and the clean out any spyware or data mining programs. Viruses are another problem area and you should have installed an updated a good Anti-Virus program like AVG. Computers today are running very large and complex programs that are really taxing the computer resources. If you can get in to a routine of computer maintenance your computer will run faster and more efficiently. However since we are all too busy the next best option is to sue a program like Ghost or Partimage to restore the entire operating system back to a know good configuration that provides a clean registry and clean hard drive. I perform a complete restore on the 30 computers that I run in a computer lab with high school students. These students have complete administrator rights and reconfigure the computers daily as they complete lab assignments. I am able to restore all of them in about 10 minutes. This brings them back to a fresh state where they can run at their optimum. I have a some addition information and resources at a computer repair training site that has been setup for my students to help them better understand how to maintain computers. Also I have some YouTube videos that you might find helpful.
The Reboot Computer Help website has some additional information you might find useful.
understand that Windows is a very complex operating system that needs lots of help to keep it running. Windows is always at its best when freshly installed. Then it starts its slow computer death as you begin to install, configure, surf the Web, play games, run applications, and uninstall programs. It has a registry that just cannot keep up with all the many demands put on it. A good registry cleaner is needed to help correct its many ills. Also one of the leading problems is we have is too many programs and not enough available resources. You also should be running a good anti-virus program like AVG. It see free for personal use and is better than most of the commercial anti-virus programs. Also a good firewall like ZoneAlarm will help to keep both inbound and outbound traffic in check. I also recommend Adaware by Lavasoft to remove the spyware and data mining programs you pick up while surfing the Web. I have a HubPage that covers why Windows slows down in more detail at Slow Computer and another site a Slow-Computer.net you might checkout for further helps.