Even though the majority of conventional and usual process detection utilites normally show all the active processes in your system, you can`t be sure they show 100%. There are always one or two hidden ones that you can`t see. For these cases you need a free tool like Process Revealer Free Edition.
It is a utility that shows you all those hidden active processes that don`t show up after the first check. For each process that Process Revealer Free Edition finds it will indicate the program it is associated to. Thus, if it`s a spyware or other malicious program, you`ll know quickly.
Once detected Process Revealer Free Edition lets you easily delete it and stop it from running in a hidden way, that might negatively affect your system.