Have you checked if there are any BIOS updates for your ThinkPad?
Even though your error points to VMNetSrv.sys, the actual problem could be deeper than that, but only showing up at the topmost level (your vm).
I'm not sure what your 'network enhancer' does. But along with checking for the latest BIOS, I would also make sure all of your network adapter drivers are updated to the latest.
If you STILL get BSOD, try removing variables. Such as disable all of your network adapters and see if it still BSODs, if it does, then see if it BSODs without Virtual PC installed. My guess is that the issue will disappear if you disable the network adapters.
Also, there might be two ways to disable the network adapter, one is in the adapter control panel settings. The other is in the device manager itself, where you can actually disable the device directly (which might prove to be better results) because then no driver is even loaded for it.
Update on your results for more troubleshooting info.