Method 1: Disable Blur Effect on Sign-in Screen Background by Turning off Transparency

1. Open the Settings app and navigate to Personalization -> Colors. On the right side, turn off the Transparency effects toggle switch.

   

2. Log off your user account and the sign-in screen will show a clear background picture. But you’ll lose the transparency effects across the desktop and apps.

   

If you just want to turn off acrylic blur effect for the sign-in screen without disabling the transparency effects across the system, then use the following methods.

Method 2: Disable Blur Effect on Sign-in Screen Background via Group Policy

1. Open Local Group Policy Editor and navigate to: Computer Configuration\Administrative Templates\System\Logon. On the right side, double-click the “Show clear logon background” policy to edit it.

   

2. Select the Enabled option. Click Apply and then OK.

   

3. Restart your computer. The Sign-in screen will show a clear background without enabling the blur effect.

Method 3: Disable Blur Effect on Sign-in Screen Background via Registry Editor

1. Open Registry Editor and browse to the following location: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System. If you do not have the System key, then just create it.
2. In the left pane, right-click on the System key, select New, and click on DWORD (32-bit) Value.

   

3. Name the newly created DWORD DisableAcrylicBackgroundOnLogon and set the value from 0 to 1.

   

4. Close Registry Editor and reboot your system. The next time you see the sign-in screen, you should see a clear background. If you want to enable blur effect for the logon background later on, just change the value of DisableAcrylicBackgroundOnLogon back to 0.

That’s it!