i call it the Explorer in a Separate Process Bug
the problem is likely that you've enabled 'Launch folders in a separate
process' (Explorer, Tools menu, Options, View tab, Advanced settings). what
is supposed to happen when this option is enabled is that additional
launches of explorer.exe open in their own (separate) process, BUT what
actually takes place is that only ONE additional instance of explorer.exe is
started for ALL future explorer launches AND (this is the important part),
that second explorer.exe process is started with HIGH priority. what
happens next of course is that the HIGH priority explorer.exe process
preempts all other processes (running at normal priority) when it launches,
and if you happen to be opening a folder containing objects with a lot of
metadata (like mp3s, etc), this explorer.exe running at high priority will
suck-up all cpu cycles as it processes the objects in the folder. that's
why if you've got music or video going in a media player at the same time
the new explorer is launched, the music/video will stall momentarily (the
player is running at normal priority and gets preempted by explorer).
the simplest work-around for this bug is to disable 'Launch folders in a
separate process' (disabled is the default) which will cause all instances
of explorer to launch as a child of the main (desktop) explorer.exe process,
which is running at normal priority.
the other work-around is to use the task manager to manually change the
priority of the second instance of explorer.exe (right-click on explorer.exe
process running at high priority and choose Set Priority, Normal) keep in
mind, when the second instance of explorer.exe is closed, the next time
explorer is launched, you will have to adjust its priority again.
(incidentally, i've reported this bug to microsoft on several occasions, but
they have neither acknowledged my e-mail nor the problem itself)
