SpotlightDL

This program can retrieve Windows Spotlight images by requesting the Microsoft Spotlight API. SpotlightDL can also define images as wallpaper and system-wide lockscreen image.

It is useful in the following use cases:

Download the whole Spotlight library with maximum image resolution and metadata
Define Spotlight images as wallpaper, not only on Windows 10 but also on previous versions
Define Spotlight images as global lock screen on Win7/8/10, removing the ads on Windows 10
Chain SpotlightDL with your own scripts and apps by taking advantage of the url mode

How to use

Simply call SpotlightDownloader.exe from the Windows command prompt and see usage. The download/url modes should also work on Mac/Linux using the Mono framework.

A few Batch files are offered for ease of use for common tasks:

spotlight-download: Download Spotlight images
update-wallpaper: Set images as desktop wallpaper
update-lockscreen: Set images as system-wide lockscreen
restore-lockscreen: Restore default system-wide lockscreen
generate-manual: Generate a text file with command-line usage

If you wish to periodically update your wallpaper or lockscreen, you can schedule one of the provided script by following these instructions.

How it works

Spotlight API

The Spotlight API is located on the following endpoint:

https://arc.msn.com/v3/Delivery/Cache?pid=209567&fmt=json&rafb=0&ua=WindowsShellClient%2F0&disphorzres=9999&dispvertres=9999&lo=80217&pl=en-US&lc=en-US&ctry=us&time=2017-12-31T23:59:59Z

Where the expected arguments are:

pid : Purpose currently unknown
fmt : Output format, e.g. json
rafb : Purpose currently unknown
ua : Client user agent string
disphorzres: Screen width in pixels
dispvertres: Screen height in pixels
lo : Purpose currently uknown
pl : Locale, e.g. en-US
lc : Language, e.g. en-US
ctry : Country, e.g. us
time : Time, e.g. 2017-12-31T23:59:59Z

The JSON response contains details about 6-7 images including image url, title, sha256, ads, etc.

Spotlight API URL was originally found in this file, thanks to the author for their findings!

Global lock screen

The global lock screen image for Windows 8 and 10 is stored as C:\Windows\Web\Screen\img100.jpg. SpotlightDL backups the image as img200.jpg if it does not already exists, then overwrite this file. The lock screen image cache, located at C:\ProgramData\Microsoft\Windows\SystemData\S-1-5-18\ReadOnly\LockScreen_Z, must be cleared for the change to take effect.

SpotlightDL gets around NTFS permissions on these folders being locked down to TrustedInstaller by setting the local Administrators group as new owner of the relevant files and folders, and granting full control to this group. Then, programs running as administrator can overwrite the lockscreen image and clear the cache.

This way of replacing the lockscreen is basically a C# implementation of this script, avoiding the use of the takeown and iacls commands which are not reliable due to a localization issue.

Windows 7 support is also implemented through the OEMBackground feature:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background]
"OEMBackground"=dword:00000001

Then the image has to be placed in C:\Windows\System32\oobe\info\backgrounds\backgroundDefault.jpg Windows 7 enforces a limit of 250 KiB so SpotlightDL will recompress the image to the highest quality fitting in that limit.

License

SpotlightDL is provided under CDDL-1.0 (Why?).