I tried to join my Windows 7to 2003 AD in mixed mode,I started the wizzard I got the error :"Your computer could not be joined to the domain because the following error has occurred: The spezified domain does not exist or could not be contaced."Netbios over TCPIP is activated and I can ping the NT4-PDC-Emulator and can browsethe NT4-PDC-Emulator, too.I made the changes in the Local Security Policy as I red in this forum.My Windows 7 runs on VMware Workstation.

Hdru,Post the contents from the %windir%\debug\NetSetup.LOG file here.Then can we help you to analyze your join problem.Kind RegardsDFTIM me - TWiTTer: @DFTER