I've always just manually disabled the shortcut from control panel.
I guess there is a way to do it programmically using some Windows specific code, but that can't be done with JavaScript in a browser.
It could possibly be done from an addon for a nwjs, but that doesn't seem like a very simple thing to do.
Do modern games use shift key? I know \ got blacklisted (shame, best key for squats in fps) but I'm not sure if the kids use shift or not, I like it, sits nicely above ctrl.