Upgraded from Duo to Quad, Windows Media Player Network Sharing Service fails

I took advantage of the $199 price for a Core 2 Quad processor at
Microcenter and upgraded my Intel DG965 from a Core 2 Duo to a Core 2 Quad.

Everything works fine, but when Vista 64 Home Premium SP1 starts I get
multiple failures of the Windows Media Player Network Sharing Service. I
finally resolved it by going into WMP and disabling network sharing, which I
can live without for now.

Anyone ever seen this before, or have any idea why the Windows Media Player
Network Sharing Service would fail after changing out the CPU? Everything
else seems to be fine, Device Mangler shows the 4 new processors, and Task
Manager shows 4 CPUs.

I've got an Nvidia 7600GT video card, 4GB of RAM and SATA hard drive for
what it's worth. I was thinking about just reinstallng from scratch on the
new CPU, but would prefer not to do this if I can avoid it.

Thanks!