Skip to content

Windows Defender (Antivirus)

On this page

Recommendation

Leave as default

Leave enabled.

When a compatible third-party antivirus is installed, Windows itself switches the components into the appropriate mode. Do not disable Defender manually just for FPS.

Application
Only via “Apply”
Main effect
Disabling the antivirus
FPS and memory
See the research

What changes

Section titled “What changes”

The setting controls the built-in Windows antivirus. According to the visible BoosterX description, when Defender is disabled it is put into a disabled state and its background scans stop; when enabled, protection returns. Protection itself stops scanning launched and loaded objects until it is turned back on.

The actual state is additionally controlled by Tamper Protection, an organization policy or a registered third-party antivirus — the BoosterX toggle is not the only source of truth.

Exceptions and differences

Section titled “Exceptions and differences”

Mechanics of application. When changed, BoosterX shows a separate security warning: “This setting may degrade system protection. Apply at your own risk.” The setting is excluded from “Instant apply”: the change takes effect only after pressing “Apply”, even if instant mode is enabled globally. A confirmed reboot is not mentioned in the description — do not require it and do not expect it.

In BoosterX this setting is linked to AMSI: according to the visible app description, when Defender is disabled the behavior of AMSI also changes. If scanning interferes with operation, first update the databases and check active scanning; add an exclusion only for a specific trusted folder.

How to verify the result

Section titled “How to verify the result”

The visible sign is “Windows Security”: after disabling, the app reports that no active antivirus is present (BoosterX mentions this directly). Open Settings → Privacy & security → Windows Security → Virus & threat protection and check the message; after the setting is reverted, active protection is confirmed there as well. Make sure the choice is not overridden by MDM or your organization’s Group Policy.

How to change and revert

Section titled “How to change and revert”

In BoosterX, open “Optimization” → “Security” → “Windows baseline protection” → “Windows Defender (Antivirus)” and move the toggle to “Off”: BoosterX will apply the default Windows state with Defender enabled. Press “Apply” at the bottom of the page — “Instant apply” does not work for this setting. To disable the antivirus, move the toggle to “On”, confirm the security warning and press “Apply”; to restore protection — “Off” again and “Apply”.

Confirmation

Section titled “Confirmation”

Last checked: 2026-09-19.