How do I turn my NEI on in Minecraft?

I have installed NEI onto my minecraft and it was there when i logged off my world but when I went back onto my world my NEI wasn't there.

Does anyone know where or what button I press to get my NEI back as I really need it?

Solution 1:

Try enabling NEI in the inventory by pressing "o", if that doesn't work identify that the mod is installed by clicking the mods button, If the mod is not in that list re-install it.

Solution 2:

Press the O key, it's the default for turning the mod on/off. Check if the mod is installed correctly as well. If it isn't installed that could be your problem!