As I write this article I will be working on a customer's PC. When the customer brought it in her complaint was that the PC was just slow. It takes five minutes to start up, almost as long to launch programs, and over a minute to open her browser. I will walk you through the steps I take to solve these basic problems.
When I start the computer, it's obvious that there are way too many programs trying to start at the same time. So what I am going to do is go to the start menu click run and type "msconfig." I click on the start up tab and uncheck any programs that aren't needed (if you don't know what a program is is then leave it checked for now and do a Google search later to see if it's needed).
When I restart there is an obvious increase in speed but there is still room for improvement. Okay this is where most people would check for viruses, but if you have a decent anti virus program chances are it would have already told you have a virus and removed it for you. (if you don't I recommend AVG. The more likely cause is the registry, now I don't want to over whelm you so I won't go into detail about the registry all you really need to no is how to fix it.
I use and recommend to all my customers a program called Registry Easy - this will clean and repair your registry for you. Next I use Spybot search and destroy. Spyware is more common than then viruses and infects almost every computer that is brought to me. Again this program is pretty self explanatory.
The next step is to defragment the system, yeah you have probably done this using windows defrag tool, this helps but third party tools like jkdefrag or my personal favorite Mydefrag do a much better job. These programs are pretty self explanatory so I won't go into detail. These steps are what I consider basic computer maintenance and done periodically will definitely save you an expensive and stressful trip to the repair shop by speeding up your computer yourself.