Security
Various programs designed to keep your computer clean.
Bit Defender
Bit Defender is an anti-virus program. They offer a free anti-virus in addition to paid subscriptions. Reccomended for Windows XP as it is light and doesn't use many resources.
Microsoft Security Essentials
Microsoft's Free anti-virus for Windows. Not recommended for Windows XP. Light weight and easy to use. Most of us at the shop use this on our home computers.