Whenever I start the Virtual PC 2007 console the network performance of
the host drops dramatically. Why is that?
Note: I do not start any virtual machines yet, just the console!

More detail:
Host: Vista SP1, Core2 Duo, Gigabit on motherboard.
Other PC in network: XP SP2, Gigabit network card.

I start copying a large ISO file from the XP machine to the Vista host.
Network speed is around 30-40MB/s, quite acceptable.
However: as soon as I start the Virtual PC console (again: just the
console, no machines yet) the network speed immediately drops to just
around 7.2MB/s (quite constant actually). When I close the Virtual PC
console the speed rises in a few seconds back to 30-40MB/s.

Can anyone explaing this?

(note: I installed Vista SP1 just a few days ago but I have experienced
varying network speeds before that too, just didn't discover the direct
relation to VPC)

VPC may initialize for playing sound, which in turn makes Windows Vista slow
down the network. Known issue, Microsoft doesn't think this is a problem -
you should finally recognize that Vista sucks.

In article <6549eqF2efn4dU1@mid.dfncis.de>, seppi@seppig.de says...
Thank you, you pointed me in the right direction. I followed the advise
on
http://blogs.technet.com/markrussinovich/archive/2007/08/27/1833290.aspx
and disabled the Multimedia Class Scheduler. Now my network speed no
longer drops when starting VPC.