There are a few good tools that come with Windows which are called Disk Defragmenter and Disk Cleanup. These tools are very reliable and can increase the speed of a computer drastically.
A good AntiVirus program to use is Norton AntiVirus. NAV is available for purchase at our location.
When you have an AntiVirus and SpyWare program make sure that you keep these programs up-to-date. All programs such as this comes with an Automatic update which can be set at different times of the day to fit your needs.
Also, if you have Windows make sure that you run Windows Update often because Microsoft comes out with a lot of Security fixes.