I have almost everything keyboard-related in the accessibility settings in Windows disabled and I still can't stop the OS from beeping every time Ctrl and Shift are pressed together.
I'm not sure or don't think it's related to "sticky keys".
Does anyone have any idea what could be causing this and how I can stop it?
Control Panel\Ease of Access\Ease of Access Center\Make the keyboard easier to use
if everything's disabled (i.e. Mouse/Sticky/Toggle/Filter Keys) I don't really see anything else that would make the PC beep with a single Ctrl+Shift combo. Some software might be responsible I guess. What's getting loaded at startup? Have you tried disabling everything? Does the issue occur in Safe Mode too?