It looks like you have core isolation memory integrity enabled or more likely, you are using some other Windows feature like WSL2. Follow the disable VBS link in my signature.
Edit - Some users have to disable a virtualization setting in the BIOS. It might be called VT-x or something similar to that. If you are still having problems, post a screenshot of the Windows Features list. Anything that depends on virtualization needs to be disabled. If something like WSL2 is a must have, you will not be able to use ThrottleStop to adjust the CPU voltage while running Windows.
Delete the ThrottleStop.INI configuration file after you disable VBS.
The All Core buttons will show multiplier values like 55, 56, 57, 58 when ThrottleStop is working correctly and has full access to the CPU voltage control register.
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You can also run msinfo to check if Virtualization based security is enabled or not.
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