Random usability rant: I find it slightly odd that, even now on Windows 8, keyboard customization requires so much effort in Windows. For example, I always make my capslock key an extra control key (if you haven't tried this before - try it!) and on OS X and most flavors of Linux, this is an easy 5 second process.
On Windows 8, there are a ton of Keyboard settings - including promising-sounding ones like "Change how the keyboard works" and "Keyboard properties" - yet you still have to use a stupid registry hack to actually change the behavior of keys (ie, to make your capslock key an additional control key).
While I agree that it should be easy to change, in reality it works out to be 5 minutes of Google and 1 reboot over the lifetime I have the OS installed. Since Window 7 I don't re-install the OS very much these days so its not that big an issue.
I make my capslock a backspace. Seriously, when do you really need to type so many capitals that can't just be rationalised by using Shift instead? Using it as Control as well is a great idea! You should first try out Autohotkey, instead of resorting to registry hacks.
Cheers
Ah, remapping it to backspace is kind of interesting. The reason remapping it to control works well for me is that most of the keyboard shortcuts I use for things (and I use a lot) use it, so remapping the capslock key to it helps you keep your hand on the home row more.
On Windows 8, there are a ton of Keyboard settings - including promising-sounding ones like "Change how the keyboard works" and "Keyboard properties" - yet you still have to use a stupid registry hack to actually change the behavior of keys (ie, to make your capslock key an additional control key).