Are you bored setting up domain controllers for your demos to work with, not sure of all the prompts to fill in then try this on a clean copy of Windows Server 2008 R2..
Create a text file called NewDC.txt and copy this into it..

[DCINSTALL]
InstallDNS=Yes
NewDomain=forest10
NewDomainDNSName=Contoso.com
DomainNetBoisName=domain
ForestLevel=3
DomainLevel=3
DatabasePath=%systemroot%\NTDS
Logpath=%systemroot%\LOG
RebootonCompletion=yes
SYSVOLPath=%systemroot%\SYSVOL
SafeModeAdminPassword=
on the last line you’ll want to add your own password to the SafeModeAdminPassword.
Save the file and then enter this command:
DCPROMO /unattend:NewDC.txt
and your done. except you might also want to put some accounts in there.  Powershell is your friend here, and if you need a regular script to do this don’t forget my favourite powershell command:
Set-ExecutionMode unrestricted
which allows you to run any old script  (usually with a .ps1 extension). Here’s a typical script I use..
Import-Module ActiveDirectory
New-ADUser -SamAccountName SQLService -Name "SQLService" -AccountPassword (ConvertTo-SecureString -AsPlainText "Pa55word" -Force) -Enabled $true ,DC=CONTOSO,DC=COM' -PasswordNeverExpires 1
New-ADUser -SamAccountName LabUser -Name "Andrew" -AccountPassword (ConvertTo-SecureString -AsPlainText "Pa55word" -Force) -Enabled $true,DC=CONTOSO,DC=COM' -PasswordNeverExpires 1
Add-ADGroupMember -Identity Administrators -Member SQLService   
Add-ADGroupMember -Identity Administrators -Member Andrew
Enjoy