Windows Task Manager Processes

[Manny]

When I open the Task Manager there is an excessive amount
of processes running, some of which are probably
unecessary. How can I work out whether or not they are
needed, what they do, and how to remnove them if they are
unecessary?

 

[Arecibo]

When I open the Task Manager there is an excessive amount
of processes running, some of which are probably
unecessary. How can I work out whether or not they are
needed, what they do, and how to remnove them if they are
unecessary?

http://www.answersthatwork.com/Tasklist_pages/tasklist.htm

Arecibo