I'm just going to go to page 1 of my computer technician handbook, and say what it says there. That has always solved the problem. Here, let's see.....

1. Is it turned on?
-IT SHOULD BE
2. Are all the wires plugged in on BOTH ends?
-Had that problem yesterday
3. Are you connected to the wireless?
4. Is your wireless working?
-You'll probably need a new one if it's not.
5. Do you connect, but can't control anything?

I have tons more questions if you need any!