I don't think Windows gives an administrator account unfettered access to the full RAM, no. And without that or the user's login password, all they could get from the registry is the encrypted version, just as on disk. The encryption is separate per-user with that user's password.
Of course there may be ways to get an even more advanced level of access than administrator, such as the system account, but honestly Windows does lock some things down really hard at the kernel level and Data Protection decryption based on in-RAM credentials might be one. I don't know modern Windows internals to that level.
Of course there may be ways to get an even more advanced level of access than administrator, such as the system account, but honestly Windows does lock some things down really hard at the kernel level and Data Protection decryption based on in-RAM credentials might be one. I don't know modern Windows internals to that level.