Windows 7: Remove "Other Credentials" button from login screen

But I need to have it tracking handles *while* I lock my computer (to see what specific program/dll is looking at that key), is there any program that will just sit and log all handles?

You can try regmon and see if that works for you.

I'm sorry this is not a solution to your problem.

But I saw you saying this:

How did you exactly manage this? I've been looking for ages for a way to do this, but all my searches came up with nothing. Is it also possible to have this aesthetic change in the Lock screen (in addition to the login screen).

See my last two posts here for info.

Basically, you create a .reg file with the two lastloggedonprovider settings and then create a vbs file to import the .reg file and add it as a logon scheduled task.