No sound apart from system sounds

Hello,
I've recently had reason installed on my laptop which was working fine. I stated writing a tune which is wicked and found I needed a keyboard for ease of use. Then i've connected a midi keyboard and before realising that i needed to download a driver for the keyboard have managed to turn something off whilst farting around in sounds and devices. Have tried to resolve problem by trouble shooting but to no avale. Can somebody help me PLEEEEEEEEEEEEEEEEEASE!

Cheers