:: Set primary and alternate DNS for IPv4 on Windows Server 2000/2003/2008 & Windows XP/Vista/7
@ECHO OFF
SETLOCAL EnableDelayedExpansion
SET adapterName=

FOR /F "tokens=* delims=:" %%a IN ('IPCONFIG ^| FIND /I "ETHERNET ADAPTER"') DO (
SET adapterName=%%a

REM Removes "Ethernet adapter" from the front of the adapter name
SET adapterName=!adapterName:~17!

REM WinXP Remove some weird trailing chars (dunno what they are)
FOR /l %%a IN (1,1,255) DO IF NOT "!adapterName:~-1!"==":" SET adapterName=!adapterName:~0,-1!

REM Removes the colon from the end of the adapter name
SET adapterName=!adapterName:~0,-1!
echo !adapterName!
GOTO:EOF
netsh interface ip set dns name="!adapterName!" static x.x.x.x primary
netsh interface ip add dns name="!adapterName!" x.x.x.x index=2
)