Windows Defender Message

Question

I have Norton installed on both desktop units. In the past 2 days, while updating software from the IoBit company, I got a Windows Defender message as to whether to proceed with the the installation/update. I've never received such a message, ESPECIALLY since Norton is installed. Is this a real message? Is there an issue with Defender? Please let me know.

Answer 1

Windows Defender is built into Windows 10 and remains present even when a third‑party antivirus such as Norton is installed. When another security product is active, Defender’s real‑time protection is normally turned off, but Windows can still show security prompts (for example, SmartScreen or installer reputation checks) when software is being installed or updated.

Seeing a Windows Defender–branded prompt while installing or updating software does not by itself indicate a problem with Defender or with Norton. It typically means Windows is checking whether the file is safe before allowing it to run. This can happen even if Norton is installed and working.

Microsoft recommends not running more than one real‑time antivirus at the same time because it can affect performance and cause update or install errors. If Microsoft Defender Antivirus real‑time protection is still on alongside Norton, it should be turned off and Norton left as the active real‑time product:

1. Select Start > Settings > Update & Security > Windows Security > Virus & threat protection.
2. Under Virus & threat protection settings, select Manage settings.
3. Ensure Real-time protection is turned Off if Norton is the primary antivirus.

Defender’s on‑demand tools (like Microsoft Defender Offline or Microsoft Safety Scanner) can still be used when needed, even if Norton is installed.

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References:

• Antivirus and antimalware software: FAQ
• Consumer antivirus software providers for Windows