I am frequently asked what I do to keep my computers running well. There are many tools out there and everyone wants you to use theirs.
The most important is an anti-virus app. Many rely on the one that came with their computer and they pay for the upgrades each year. I guess I am a "cheap geek". I have been using free ones for years and running trouble free. Now, you cannot have more than one antivirus running at the same time. They are working against each other and will slow down your machine. So if you decide to switch, remove the one you are currently running first.
I recommend going with MSE: http://windows.microsoft.com/en-US/windows/products/security-essentials
Once a week I would run CCleaner FREE to clean out the junk and clean the registry: http://www.piriform.com/ccleaner/download
I would download Defraggler FREE and run it once a week as well: http://www.piriform.com/defraggler/download
Also run Malwarebytes FREE once a week: http://www.malwarebytes.org/products/malwarebytes_free
In addition I recommend getting your email in the cloud with gmail, yahoo, hotmail, or another service. They all run your emails in and out through an anti-virus app before sending them to you or to your recipients.
And of course be wary of the emails you open and who they come from. Always check the address of any links you are tempted to take by mousing over the link first. In the lower left of your browser screen you will see the address of the site you are going to. Look funny? Don't click the link.
Hope this helped...
