Shutting down Parallels 7

Since upgrading to P7 my iMac (2011 model) has started running very slow. My 8Gb machine feels more like 4Gb.

My question therefore is, how do you completely shut Parallels 7 down without any processes running the background as I believe P7 is the reason for the depleted performance on my iMac. There are several options for closing P7 but its not entirely clear which shuts it down 100%.

Thanks