Any time you have a program running at bootup that you're unfamiliar with, just Google for the executable name, as in nvcpl.exe. There are a thousand or more sites that will give you a description of what programs an executable is associated with. Nvcpl.exe is an Nvidia display driver control panel helper applet, for instance, and can be disabled. When you open the Control Panel Display applet, that program will be automatically started if it isn't already running.