I have tried creating the service account manually before starting the installer.
Nevertheless the installer says "User account .潰瑳牧獥瀀偧獡睳牯d\潰瑳
牧獥瀀偧獡睳牯d does not exist".
The batch file is
msiexec /i postgresql-8.1-int.msi /qn INTERNALLAUNCH=1 DOSERVICE=1
DOINITDB=1 CREATESERVICEUSER=0
SERVICEACCOUNT="postgres" SERVICEPASSWORD="pgPassword"
SUPERUSER="postgres" SUPERPASSWORD="pgPassword"
PERMITREMOTE=1