Windows Security does not detect 3rd party antivirus

You need to disable the AV check. If you are using Windows 11/10 you will have to edit the Registry as follows: Run regedit and navigate to the following key: Under Feature key, in right-side pane, right-click > New > DWORD. Name it as DisableAvCheck and change its value to 1. Restart your PC and see.

If you are using Windows 7 or Windows Vista and have antivirus software installed on your Windows 7, and still the Windows Security Center or Action Center does not detect it as being installed, you may want to apply this Hotfix and see if it helps you.

Let’s say, you have a computer that is running Windows 7, and you have installed an antivirus application on the computer. You generate a system health report for the computer. In this scenario, the system health report reports that no antivirus application is installed on the computer. You may receive an error: Additionally, the following message is included in the report:

Symptom: The Windows Security Center has not recorded an anti-virus product.Cause: The Security Center is unable to identify an active anti-virus application. Either there is no anti-virus product installed, or it is not recognized.Resolution: 1. Verify that an anti-virus product is installed. 2. If an anti-virus product is installed and functioning, configure the Security Center to stop monitoring anti-virus status.

This hotfix from Microsoft uses a new WMI namespace and may help resolve the issue. Head over to KB2482947 and request a Hotfix. Windows Vista users may want to check out KB952923. See this post if Windows Security Center identifies old security software as installed.