On your macbook if you want to change MacBook pro default background login screen with you own background image of your own wallpaper background on your MacBook pro or air with MacOS Ventura or macOS Monterey or Bigsur or Catalina then you can easily change login screen background and MacBook opening screen and customize login screen background on MacBook pro or air (Ventura, Monterey, BigSur) . So, let’s see in detail below.

Changing login screen background is a little bit tricky but you can change it and in order to change login screen background you will need your administration UUID Number and first go to accounts and user and copy the UUID number of your macBook pro air and follow below methods and you need to turn off your file vault on your MacBook pro or air.
Change Login Screen Background on MacBook Pro or Air Ventura / Monterey / Big Sur
Below methods will help you change your login screen background on your macOS monterrey, ventura, bigsur, catalina and other macos with your own custom background image.
Step 1: Click on apple logo and select System Preferences
Step 2: Now, click on Users and Groups.
Step 3: On bottom -> Click on the lock to make changes
Step 4: Enter your Macbook Password and hit enter to make changes
Step 5: On the left side menu -> Select your administrator user and right click on the user and select Advanced options.
Step 6: Now, copy your UUID from the file -> Now click on Ok and exit and close all open windows on your MacBook pro or air.
Step 7: Click on Go Menu on top of the apple menu and click on Go to finder.
Step 8: Go to the folder -> /Library/Caches and click on OK.
Step 9: Now, create a new folder here and name it as Desktop Pictures.
Step 10: Right click on the Desktop pictures folder and select Get info.
Step 11: Click on Lock icon and enter your macbook password.
Step 12: Now, change the permission to read and write in order to make changes to this folder.
Step 13: Open folder Desktop Picture and create a new folder and name it as UUID number which you have copied from your users and group administrator uuid number at the beginning.
Step 14: Right click on this folder and get info and give permission to read and write.
Step 15: Copy the image that you want to set as your MacBook wallpaper in to this folder.
Step 16: Name the image file to lockscreen.png and close all open windows.
Step 17: Now, go ahead and open system preferences and then Security and Privacy
Step 18: Click on the lock icon and enter your MacBook pro or air password and turn off fault vault and turn off firewall on your MacBook pro or air.
Step 19: Now, Go ahead and Restart your MacBook pro or air and your MacBook login screen background will be changed.
Also Read:
1) How to Fix MacBook pro M1 Popping Sound When Music Playing
2) How to Fix Microphone Not Working on MacBook Pro or Air
3) How To Play PS4 On PC Remote Play on Windows PC or Laptop and MacBook
4) How to Download and install Apps on MacBook pro or Air Without Apple ID Password
5) How to Forget a WiFi Network on MacBook M1 Pro or Air MacOS Monterey
That’s it, once you make the above change and turn off filevault and firewall then your login background on MacBook pro or air on macOS Ventura or Monterey or Big Sur or any other MacOS on your macBook, your background login screen on your MacBook will be changed successfully.
Change macOS Monterey Login Screen Wallpaper
That’s it, this is how you change macOS Monterey login screen wallpaper and set desktop wallpaper on MacBook pro or air.
How to Change macOS Ventura login screen background
You can change and customize login screen on MacOS Ventura on MacBook pro or air and change login screen background on MacBook pro or air to any login background color or desktop picture as well.
MacBook Pro or Air Login Screen Not Changing
Once you make above changes and by creating a new folder desktop pictures with your UUID number and name the login background image to lockcreen.png then you need to turn off filevault and disable firewall on your MacBook pro or air in order to change login windows or login screen on your MacBook pro or air and restart your mac.
Also make sure that UUID you copy is of administrator and name the folder with the correct UUID number.
FAQ
Yes ! You can change login windows or login screen on your MacBook pro or air on any macOS Monterey or BigSur or Catalina and other macOS easily and make sure you turn off file vault once you make changes.