BGInfo for Windows 10

Years ago, Mark Russinovich of Sysinternals fame (since bought by Microsoft) released the BGInfo utility, which served two purposes: to put various system information such as the computer name and free hard drive space on the desktop, and likewise to put the same info on the lock screen. In a large environment, that latter feature was extremely useful as it enables users and technicians to quickly see the name of a PC without having to log on and find the info.

Unfortunately, Microsoft changed the way the lock screen was handled in Windows Vista and 7, which broke BGInfo’s lock screen functionality. Windows 10 changed things yet again and while BGInfo has been updated to support Win 10, we could not get it working for the lock screen. I don’t want to say it’s not possible, because there may be some combination of using the program along with group policy to display the info on the lock screen, but in our environment it did not work.

Anyway…we really wanted this functionality so I began to look into ways of hacking something together…and boy is this a hack.

Before I go any further, I want to clarify the terms I’m using:

The lock screen is the screen (wallpaper) displayed before a user has logged on, or when the logged-on user locks the computer. {WIN}+{L} for example. In Win 10 RTM and 1511, this disappears before the user is prompted for credentials.

The login screen is the screen where a user actually enters their credentials. On Win 10 RTM and 1511, this background will either be a solid color or the neon-blue Windows wallpaper. On 1607, the lock screen image will remain even once the login fields are shown.

As is seemingly always the case with Windows 10, half the battle is figuring out how aspects of the OS actually work; only then can you determine how to best control things. The below represents my best efforts at understanding what’s going on behind the scenes; if you know otherwise or can add to the discussion, please leave a comment. Also, while some of the settings below can be controlled through group policy (and one must be), I elected to deal with the registry directly as doing so kept all the changes in one place.

Additionally, the way the lock screen works is different in build 1511 (Threshold 2), 1607 (Anniversary) and 1607 with the September cumulative update. These scripts will work with either 1511 or a fully-patched 1607, at least as of this writing. They may however work differently between the two builds, as well as on an existing user profile versus a new one.

There are two sets of lock screen settings: the system-wide machine setting, and a user setting which is (predictably) specific to each user.

For the system-wide settings, we have:

HKLM\Software\Policies\Microsoft\Windows\Personalization\NoChangingLockScreen – Set to 0 to allow the user to change the lock screen, 1 to prevent changes.

HKLM\Software\Policies\Microsoft\Windows\Personalization\LockScreenImage – This is the full path to the lock screen file.

The in-box lock screens are located at c:\windows\web\screen and there does not appear to be a way to select anything other than these default images through the UI.

For the user-specific settings, we have:

HKCU\Software\Microsoft\Windows\CurrentVersin\ContentDeliveryManager\RotatingLockScreen – Set to 0 for a fixed image, or 1 for Windows Spotlight.

Windows Spotlight is a feature by which Win 10 downloads new lock screen images on its own, rotating them from time to time. If Spotlight is enabled, the below registry keys are relevant:

HKCU\Software\Microsoft\Windows\CurrentVersion\Lock Screen\Creative\HotspotImageFolderPath – Path to the user’s downloaded images

HKCU\Software\Microsoft\Windows\CurrentVersion\Lock Screen\Creative\PortraitAssetPath –> Full path to the lock screen file for portrait (vertical) layout

HKCU\Software\Microsoft\Windows\CurrentVersion\Lock Screen\Creative\LandscapeAssetPath –> Full path to the lock screen file for landscape (horizontal) layout

Now in theory, if a computer (HKLM) policy is set to prevent the user from changing the lock screen image, the user should receive the same lock screen, but what we found instead was in some cases on build 1511 the user’s setting would override the computer’s setting. In other words, we would have a fixed lock screen for the computer when nobody was logged in, but once a user logged in, their lock screen settings (which default to having Spotlight enabled) would take precedence. This meant we’d have one lock screen for the computer, and one lock screen for each user. 1607 seems to work properly in that setting a lock screen at the HKLM level prevents any user changes from being made.

On 1511, I recommend enabling the group policy Computer Config à Policies à Administrative Templates à Control Panel à Personalization à Prevent changing lock screen and login image. If you do not do this, the user retains the ability to change their lock screen even though they technically should not.

There are a lot of moving pieces here. The download includes both a startup and login script; on 1511 you need both. On 1607 you can get away with just the startup script however you will lose some functionality in doing so. Here’s what each piece does:

Startup Script

• Check if we’re running on Win 10; if not, exit.
• Choose a random picture from c:\windows\web\screen, and save it out to c:\programdata\bginfoscreens
• Determine the size of the display; this unfortunately running this at startup or shutdown is problematic, so we’re doing a few different things:
  • Attempt to determine the size; the default return value is 1024×768. If we get that back, assume we have bad info.
  • If we have bad info, attempt to read c:\program files\bginfo\resolution.out, which is a text file created by the login script, containing the correct resolution.
  • If we have resolution.out, use the resolution there; otherwise stick to the (likely incorrect) data we collected earlier.
• Resize the picture chosen earlier to our screen resolution.
• Write out our desired info to the resized picture. We attempt to adjust the text positioning to fit the image.
• There’s some code here for debugging purposes, where you can choose to display additional info on the screen if the system name matches a certain pattern.
• Save the image.
• Set the new lock screen by making changes to the registry.

Login Script

• Check if we’re running on Win 10; if not, exit.
• If you set $enablenetworkcollection to $true and provide a valid, user-writable path as $networksspath, the login script will copy the user’s Windows Spotlight backgrounds to a network share. This is useful if you want to have a larger pool of pictures for the computer lock screen. If you choose to do this, you will eventually want to disable $enablenetworkcollection and use whatever method you like to copy this collection of pictures to c:\windows\web\screen
• If you collect these images, you will need to rename them to .jpg and also filter out any that are not the proper resolution. I’ve included a quick and dirty script, “CheckResolution.ps1” which will do this.
• Determine the screen resolution; unlike the startup script, this should always be correct. We save it to a file so the startup script can access it on subsequent reboots.
• Read the registry to determine where the user’s lock screens are located; if we don’t find the keys the rest of the script is meaningless, so we exit.
• Find a random image to work with, checking if it’s 1920px wide.
• Code to save images to a network location if $enablenetworkcollection is true.
• Resize the picture chosen earlier to our screen resolution.
• Write out our desired info to the resized picture. We attempt to adjust the text positioning to fit the image.
• Save the image.
• Set the new lock screen by making changes to the registry.

The combination of these two scripts provides a lock screen that rotates on startup and on login (1511) only, as well as displays the info you choose to show. It’s a hack as I said earlier, but it works for us at least, and if nothing else it should provide a starting point for your own environment.

Download the scripts here: http://media.islipufsd.org/Scripts/BGInfoScripts.zip

Note the scripts themselves credits certain other sites and posts I’ve taken code from.

EDIT: These are tested and working on both 1709 and 1803.