An antivirus is probably the most CPU intensive process running on your computer or laptop so it is vitally important you do not have 2 installed at the same time.
If you do you will find your computer running far slower than it should be as they are both trying to use resources.
We recommend searching in “add or remove programs” and try to uninstall any redundant old antivirus providers you are no longer using and only have the one chosen antivirus installed.
So if you are reading this looking for a new antivirus provider, once you have made your decision remove your old provider before installing your new chosen AV.
For help you should be able to just Google your providers name and how to uninstall.