I assume it's disabled because you entered a wrong code or similar reason.
Here's the cure:
1. Open iTunes
2. Plug the disabled device into CPU w/ iTunes open.
3. A pass code message will pop up. Cancel it.
4. Hold the power button (button on top) and the home button (button on screen) down together until the screen goes black. Once the screen goes black count to two. Then let go of the power button while continuing to hold down the home button.
5. Your computer will eventually say the phone us in recovery mode and you will be able to restore it.