I recently lost the ability to change the IP settings on my computer and found the following post that was helpful at Scott's Newsletter Forum.
Basically the solution was get a copy of a good version of tcpip.sys, copy it to the c:\, and run the following commands form the command line recovery console. chkdsk /p del c:\windows\system32\drivers\tcpip.sys chkdsk /p copy c:\tcpip.sys to c:\windows\system32\drivers\tcpip.sys chkdsk /p

Thanks guys.