The curves function in Elements recent versions is to be found under enhance/color/ color curves. It's different from the Photoshop version and there is no adjustment layer. It is designed for beginners in that it starts from the effect you want and shows you how the curve is shaped for that effect.
If you are acquainted with Photoshop, you know that you can simulate a curves adjustment layer with a black to white gradient layer in luminosity mode.
Since you are in Windows I would advise getting the free and powerful 'smartcurve' plugin.SmartCurve Free Download - Softpedia
A lot of free or very affordable add-ons are also available : Grant's tools, Elements+...