General things that can cause tcpip.sys failures as well that I have seen are,
nic drivers corrupt - try uninstalling them in save mode and delete the driver files.
3rd party av/firewall software
as VirtualLarry said, sometime aggressive overclocking can cause data corruption
You can use WhoCrashed or BlueScreenView to see if you can get more details from the crashdump file to see if it may point to something that is loading that is calling tcpip.sys