Maybe - try it by all means but its better to just know. Press ctrl alt del and get the task manager button and use that and look it up. Better yet is to use the sys internals version :-
which has a little more info. Actually the whole sys internals suite is excellent but its a power users set of tools. The process viewer is pretty easy tho. It should just tell you who is burning all of your resources.
If it is an anti virus issue it will be with the file touched scan. Every time a file is read or written it scans it. Very slow - might not be worth it.