But I did. I tried to copy the reg key from install.wim and from the currently running win7, still no luck. I ran regedit from PE and confirmed the [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Svchost] is the same as normal win7, tapisrv service appears in two places: under "netsvcs" and "NetworkService". procmon does not give any useful information. Besides this strange problem, there is a minor problem with the ShellHWDetection service: although I set the "Start" option to "2" (auto), it won't start. even if I manually start it, it immediately stop without an error message ("the service did not return an error"). I have to do a "Scan for new hardware" in the device manager window to let it start -- Using "devcon.exe rescan" or "wpeinit.exe" to replace device manager won't work. Thanks for your help, I'll keep working on it lianzi2000