Quote Originally Posted by DaveR View Post
Okay, solved, mostly. I passed the problem to a fresh pair of eyes and he came up with a registry setting for the host pc

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\servic es\Tcpip\Parameters\disabletaskoffload=1

With a fast cpu offloading networking to the NIC is irrelevant. With a VM and the 'network' drives really being host shares offloading is actually counter-productive! Speed now acceptable, anyway.
Probably something Microsoft Virtual PC specific as I've not seen this mentioned before and it puzzles me why disabling this at the host level makes a difference. I understand a change in the guest and actually do see it mentioned that it might help for some vSphere guests.

Quote Originally Posted by DaveR View Post
Follow-up question: How much memory are you XP-in-a-VM users allocating to the VM?
I can't possibly answer this without knowing what your workload demands are as it is completely dependent on what you are running in your VM. Windows XP itself only needs about 512MB to run and can be tweaked itself to use less resources.

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Wil