Windows Registry String Value Path

Question

I'm trying to set up Lock Screen for Users. I've created a new Registry Key with the three values:

I'm using %userprofile% since I don't know all the name of users. But the Lock Screen is not changing only if I use

C:\user\pictures\Lock Screen\img.jpg

Is not possible to use %userprofile% in a Registry String Value or is there an other way?

Thank you in advance.

Where in the registry is your key? Why can't you put the image in a folder accessible by all? — harrymc, Commented Feb 10, 2023 at 15:23
The lock screen is not inside any user (on the lock screen you can select the user to login) so which user do you think it should expend to? — Yisroel Tech, Commented Feb 10, 2023 at 15:28
The lock screen image needs to be accessible by System, since no user is logged in. The default path for this registry key/policy setting is C:\windows\web\screen\lockscreen.jpg — Cpt.Whale, Commented Feb 10, 2023 at 15:52

Yisroel Tech · Accepted Answer · 2023-02-10 15:49:31Z

It sounds to me like a combination of two things.

In order for the registry to expand the environment variables like %userprofile% or %public% you need to use the REG_EXPAND_SZ value type (choose Expendable String Value when creating the value) instead of the standard REG_SZ (String Value) you have used
You're trying to use a user environment variable (%userprofile%) in the context of the lock screen which is before logging in to any user. So which user is it supposed to use? You can only use system environment variables (like %public% or %root% there.)

1 Answer 1