So you have multiple monitors and you want to set up a different wallpaper for each monitor in windows?
In windows 11 it is actually as simple as it was in windows 10. all you need to do is right click somewhere on an empty space on your desktop and click personalize personalization settings will open look below for a tile named background click on that and the image selection will appear you can choose any image file by selecting browse photos but for this example i will use the recent images that are built in in windows so all you have to do is right click on the image and a small menu will appear where you can set the same image for all monitors or set a specific image for a specific monitor in this case we can set one picture for monitor one and one picture for monitor two if you have more than two monitors attached and active in windows the settings will go set for monitor 3 set for monitor 4 and so on so from here you can very easily select a different wallpaper for each of your displays