Could be one of several issues.
First to get back into OSX simply enter bootcamp on the Windows side and select OSX for your next boot. Once in OSX run updates, especially those related to bootcamp and your keyboard. When you are prompted to reboot make sure you first select boot to OSX from bootcamp. Once you are rebooted and all the updates are in place, open up disk utilities, select your HD and then select verify permissions... once that's finished repair permissions.
If you are still having issues after that please let us know. Hope this helps