Starting with Windows 10’s May 2019 Update, the login screen uses the blurred “Fluent Design” transparency found on the taskbar, Start menu, and elsewhere. If you’d like to see your lock screen background clearly, here’s how to disable the blur.
If you disable the lock screen, Windows 10 jumps right to the login screen instead, bypassing it. With the recent update, the background image has become distorted beyond recognition due to the “Acrylic”-style transparency effect used throughout Windows. Depending on what version of Windows 10 you have, these methods will bring clarity back to your background.
The Easy Way: Disable Transparency System-Wide
If you don’t like the look of the transparency effect, you can easily turn it off for all aspects of Windows 10. This will disable it not just on the lock screen, but also on the taskbar and right down to the Calculator or People apps. This method is an all-or-nothing approach and should only be disabled if you don’t enjoy the look anywhere on your desktop.
Open the Settings app and head to Settings > Personalization, or right-click an empty space on the Desktop, then click on “Personalise.”
Select “Colors” at the left side of the Settings window, scroll down until you see the option labeled “Transparency Effects,” then set it to “Off.”
To undo this change and enable the transparency effect on Windows 10, you can return here and toggle this feature to “On.”
Home Users: Disable Background Blur via the Registry
If you have Windows 10 Home, you’ll have to edit the Windows Registry to make these changes. You can also do it this way if you have Windows 10 Professional or Enterprise, but feel more comfortable working in the Registry as opposed to Group Policy Editor. (If you have Pro or Enterprise, though, we recommend using the easier Group Policy Editor, as described in the next section.
Standard warning: Registry Editor is a powerful tool and misusing it can render your system unstable or even inoperable. This is a pretty simple hack, and as long as you stick to the instructions, you shouldn’t have any problems. That said, if you’ve never worked with it before, consider reading about how to use the Registry Editor before you get started. And definitely back up the Registry (and your computer!) before making changes.
You should also make a System Restore point before continuing. It’s never a bad idea and couldn’t hurt to make one manually—that way, if something goes wrong, you can always roll back.
Then, open the Registry Editor by pressing Windows+R on your keyboard, type “regedit” into the box, and press Enter.
Navigate to the following key in the left sidebar, or paste it directly into the address bar at the top:
Right-click the Windows key, select New > Key, then name it “System,” and hit Enter.
Right-click the System key, select New > DWORD (32-bit) Value, then name it “DisableAcrylicBackgroundOnLogon.”
Double-click the DWORD you created and then change the Value Data from “0” to “1”.
You shouldn’t have to restart your computer for this change to take effect. Just press Windows+L to lock your computer, and you’ll see the login screen with the background image in full focus, no blur added.
To undo this change, you can just return here, locate the “DisableAcrylicBackgroundOnLogon” value, and delete it or set it to “0”.
Download Our One-Click Registry Hack
Rather than editing the registry yourself, you can download our “Disable Background Blur” registry hack. Just open the downloaded .zip file, double-click the “DisableBackgroundBlur.reg” file, and agree to add the information to your registry. We’ve also included an “EnableBackgroundBlur.reg” file you can use if you’d like to undo your change later.
You don’t have to restart your computer. The change should take effect immediately, and you’ll see it the next time you lock your PC (press Windows+L).
These .reg files just change the same registry settings we outlined above. If you’d like to see what this or any other .reg file will do before you run it, you can right-click the file .reg and select “Edit” to open it in Notepad. You can easily make your own Registry hacks.
Pro and Enterprise Users: Disable Background Blur via Group Policy
If you’re using Windows 10 Professional or Enterprise, the easiest way to disable background blur is by using the Local Group Policy Editor. It’s a pretty powerful tool, so if you’ve never used it before, it’s worth taking some time to learn what it can do. Also, if you’re on a company network, do everyone a favor and check with your admin first. If your work computer is part of a domain, it’s also likely that it’s part of a domain group policy that will supersede the local group policy, anyway.
You should also make a System Restore point before continuing. It’s never a bad idea when tinkering around and couldn’t hurt to make one manually—that way, if something goes wrong, you can always roll back.
First, launch the group policy editor by pressing Windows+R, type “gpedit.msc” into the box, and press Enter.
Navigate to Computer Configuration > Administrative Templates > System > Logon.
Locate “Show clear logon background” in the right pane and double-click on it.
Set the “Show Clear Logon Background” to “Enabled” and then click “OK.” You’ll have to restart your PC before the change takes effect.
If you have the lock screen disabled before you enable this setting in the Group Policy Editor, for some reason Windows will revert it to default—on again. All you have to do to bypass the lock screen is to run through our guide and re-add the registry value.
More Information: howtogeek.com