Tried to install antivirus, but told I have one running already?

First of all, sorry in advance for the ignorant question. I tried to download a free antivirus software (AVG) and it went through the process until at the end it told me I already had an antivirus running and having multiples running might cause a problem. Thus, the installation did not complete. However, I don’t believe I have any other antivirus on the computer currently. I did have CA Security Suite, but recently uninstalled it. I have since double-checked and there is no indication that CA remains on my computer or that its un-installation did not take, nor is there any indication that I may have another antivirus currently in place. Does anyone have thoughts on why AVG thinks I might already have something else installed? Is there a way to bypass this problem and install it anyway since I think they're wrong, or in the alternative is there a way to find out what AVG thinks I might already have? Thanks, and have a nice day.

 

You might want to check at the CA website and see if they have any utilities that COMPLETELY uninstalls and cleans everything off. Security apps/suites are notorious for leaving remnants behind causing troubles.