I would say dont make comments like :-
This box currently has 62 active processes and is running fine
Or
if something eats vast quantities of memory and actually uses it, so as to cause paging, then that can result in dramatic slowness, characterised by continuous disk noises and the disk light permanently flashing.
Unless you really know what goes on at the lower level.
Between each version of windows, windows update etc, along with your hardware setup there will be many different things installed that may need either a driver or assistance. Dont let people here fool you into thinking they are not required.
What was it you eneded - was it the process dwm.exe? If it was then there is a simple explanation why - if not please describe the process you killed. - cheers