How do I get my laptop mouse to work?

I installed my Wacom Bamboo tablet to my computer just over a month ago. They've worked fine before, but I was just using it and when I went to use my touchpad, nothing happened. It's not responding to anything I do. I tried the resetting it to use the touchpad instead through Control Panel > Devices but when I click "ok", there is no effect and when I go back to do it again, it has gone back to "Other pointing devices". Any tips? :(