Check the icons in the Notification Area, where the clock is. Hover the mouse over each icon and make a note of each. You can then use Google to check what you have.
As far as I am aware all anti-virus scanners place an icon there, so you should be able to find out.
Any Windows system should only have one anti-virus scanner, so if you have more than one you need to consider which one to stay with and which to stop using and uninstall.
Once you find out, it is important that your anti-virus scanner is kept up to date, and that means both Program updates and Virus Definition updates.
I hope that helps.
Mark
My Dell laptop continues to pop up a window from AVG asking me to install the latest version for free. But I can't remember if my anti-virus software, or the version that came with the computer is an AVG product and therefore would it mess with whatever protection I already have. Second: how and where do I go to see what is already installed to protect my computer. Sorry, sort of new to all this stuff. thanks so much.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic