WMI (Windows Management Instrumentation) filters exist within the GPMC and allow you to dynamically determine the scope of Group Policy objects (GPOs) based on attributes of the target computer.
1. To make Filters that distinguishes between XP and Win 7 computers open the GPMC, find the folder under your domain labeled “WMI Filters”, right click and select “New…”
2. The following Filter will only return true if the computer is running some form of Windows XP
3. This Filter will return true and only apply its policy to Windows 7 Machines
4. To apply these WMI to Policies look for the drop down box under any given GPO
1. Create a new GPO with the name “Login Screen XP Machines Only”. Edit the GPO and go to Computer Configuration->Preferences->Windows Settings->Files. In here you want to Right Click the blank space and choose New…->File. Here you want to type in the full path* of your wallpaper** and where on the computer you want it placed. Click Apply.
* The source path can be a network folder, but you should be very sure that all the computers within the scope of the policy are able to read that location before User Authentication.
**Wallpaper must be in Bitmap format for Windows XP machines.
2. Next Go to Computer Configuration->Preferences->Windows Settings->Registry. Right Click. Select New…-> Registry Item and configure the pictured Registry entry to replace what is already listed on the target computers.
3. At this point you can leave the GPO editor and apply a scope to your policy. Be sure to use the Windows XP only WMI filter to prevent your policies from negatively impacting non-XP computers in your network.
1. Start a new GPO called “Login Wallpaper Windows 7 Machines”
2. Edit the policy and go to Computer Configuration->Preferences->Windows Settings->Files. This time you need to use the replace action to put your image* at the destination %windir%\System32\oobe\info\backgrounds\backgrounddefault.jpg
Remember that this location cannot be altered and this file name must be used.
*Your image must be a JPEG and it must be smaller that 250kb
3. Next you want to go to Computer Configuration->Policies->Administrative Templates->System->Logon and change the setting “Always use custom logon background” to Enabled
4. Once this is done you can Close the GPO editor and apply a scope to your GPO. Also please do not forget to apply your Windows 7 Only filter to this policy.
If you’ve completed the policy correctly you should see the setting changes take place within a few minutes, but you can always prompt a policy update by entering “gpupdate” into the command prompt of a windows computer. This setup allows you to easily change your wallpapers by navigating to your source locations and replacing the wallpaper images with different ones with the same names. Just be sure that your XP Wallpaper is a .bmp file and your Windows 7 wallpaper is a .jpg under 250KB in size.