[dba-Tech] Multi-Core Processors

Dear List(s):
 
In order to take advantage of multi-core processors, do the applications
need to be modified?  Or is it taken care of by the operating system or the
chip?
 
IOW, I start an access app, open an mdb, then I retrieve my email from
Outlook.  Do those two apps run in separate cores theoretically improving
the response time?  Does the Word doc I open then run in a third core (of a
presumably quad core processor).
 
And if I open the file open or save dialog box in an app like an Office app,
does that run in a separate core?
 
I'm trying to decide if I need/should get dual, quad, or hex core processor
in a new comp.
 
MTIA
 
Rocky