---
title: "Stop Microsoft Defender from scanning during games: scheduled scans and the CPU limit"
description: "Microsoft Defender runs scheduled scans in the background and may use half the processor while it does. What it changes, when it hurts, and how to undo it."
url: https://frozentweaks.com/tweaks/limit-defender-scans
author: Frost LIVE, Founder of Frozen Tweaks
published: 2026-10-08
updated: 2026-10-08
category: "Security"
source: Frozen Tweaks (https://frozentweaks.com)
---

# Stop Microsoft Defender from scanning during games: scheduled scans and the CPU limit

**Short answer:** Microsoft Defender runs scheduled scans in the background and may use half the processor while it does. This tweak disables the scheduled scan tasks and lowers Defender's scan processor limit to 10 percent. Real-time protection stays on.

## In the app

- Switch: Tame Defender Scans (Security, Pro, Advanced)
- Undo: Yes. Switching it off turns the scheduled Defender scans back on and sets the scan CPU limit back to 50 percent, the value Windows ships with.
- Catalog row: https://frozentweaks.com/tweaks#t-1023

## What it does

Microsoft Defender runs scheduled scans in the background and may use half the processor while it does. This tweak disables the scheduled scan tasks and lowers Defender's scan processor limit to 10 percent. Real-time protection stays on.

In the app the switch is called "Tame Defender Scans", described there as: Disables Defender scheduled scans and caps scan CPU load at 10 percent.

## When it helps

- Sudden frame drops that line up with a Defender scan (Antimalware Service Executable in Task Manager).

## When it hurts

- No automatic full scans: files that were on the PC before a threat was known are only checked when you scan by hand.
- Run a manual scan now and then.

## What it writes

Read from the app's source. "Switching it off" is what the app writes when you turn the tweak off again.

This tweak has no fixed list of registry values: it works through a driver's own settings, scheduled tasks or values that differ from PC to PC. The app reads what your PC has and changes only that.

## How to undo it

Switch the tweak off in Frozen Tweaks.

## Verdict

A reasonable trade, because real-time protection is untouched. Do not combine it with switching Defender off.

## Questions

### Is "Tame Defender Scans" safe to switch on?

A reasonable trade, because real-time protection is untouched. Do not combine it with switching Defender off. The main cost: No automatic full scans: files that were on the PC before a threat was known are only checked when you scan by hand.

### How do I undo it?

Switch the tweak off in Frozen Tweaks. Switching it off turns the scheduled Defender scans back on and sets the scan CPU limit back to 50 percent, the value Windows ships with.

### Is "Tame Defender Scans" free in Frozen Tweaks?

It is part of Frozen Pro and Elite. You can also make the change by hand with the values on this page.

## Related guides

- [How to Fix Stuttering and Frame Drops: Diagnose Before You Tweak](https://frozentweaks.com/guides/fix-stuttering-frame-drops)

## More tweak explainers

- [Hyper-V hypervisor](https://frozentweaks.com/tweaks/disable-hyper-v-hypervisor)
- [SmartScreen](https://frozentweaks.com/tweaks/disable-smartscreen)
- [Remote Registry and Remote Assistance](https://frozentweaks.com/tweaks/disable-remote-registry-and-remote-assistance)

---
Written by Frost LIVE, founder of Frozen Tweaks. Canonical version: https://frozentweaks.com/tweaks/limit-defender-scans