Unable to UNINSTALL CA Anti-virus on my Windows 7 laptop

I'm trying to download Norton Antivirus 2012 on my Windows 7 laptop, and I cannot Uninstall CA Anti-virus Plus or CA

Internet Suite (anti-virus). 

 

Can anyone help me? I believe the CA Anti-virus was installed when I bought my laptop in 2010 by the folks

at Best Buy. 

 

Any help would be greatly appreciated!

Thank You!

Mindy