Odd numlock behaviour

My numlock key stopped working and I can't seem to figure out why. It is not the usual case of the mouse keys accessibility feature: it is disabled and so is the convoluted shortcut that can turn it on accidentally. It is not a hardware issue either, other keyboards show the same symptom on this PC be it USB or PS/2. Same story in safe mode.

The exact behaviour is the following:

- inside bios: works perfectly
- windows login screen: stuck in state set by HKEY_USERS\.DEFAULT\Control Panel\Keyboard\InitialKeyboardIndicators
- logged in: stuck in state set by HKEY_CURRENT_USER\Control Panel\Keyboard\InitialKeyboardIndicators

Last thing I recall doing before I noticed the odd behaviour was setting up windows remote desktop protocol and sure enough google found several threads and a microsoft support article regarding the connection between remote desktop and numlock desync issues. Still reverting all changes and disabling remote desktop did squat.

I can force numlock into either state by editing the InitialKeyboardIndicators reg value, denying admin edit permissions and relogging. I can also toggle numlock via the on screen keyboard feature, even the keyboard LED responds accordingly. Still the actual numlock key remains non-functional.

I have autohotkey, logitech gaming software and keytweak installed but haven't touched them in months, no other software I can think of that has much to do with keyboard behaviour. What else... Running win 7 ultimate sp 1 with all updates, no sign of infections according to NOD. I am out of ideas, so is google. Any suggestions? :/

Scratch that, mix of bad luck and my stupidity. Turns out years ago I disabled numlock in keytweak and set InitialKeyboardIndicators to 2 so that I would never turn it off by accident. Except I totally forgot about that and when I recently connected through RDP the desync bug reset my registry value to off and I tried to restore the default windows behaviour instead of the one I set up in keytweak.