Installation Error

My paid subscription on AVG internet security suddenly stopped working. it didn't open so i couldn't uninstall from software. I manually deleted all avg related files including the one on library and tried to install the app again but it gives this error "Installation Error: AVG Antivirus is already installed
 please uninstall the previous version first".
Please help me out to relieve this issue. I have OS X ElCapitan 10.11.6.

Hi, Korhan

We will help you in this.
Could you share us the screenshot of the error message? 
Refer this article for the steps to capture the screenshot : https://bit.ly/2Y6RCDP
You can post the screenshot here in your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions.