You might need to set the Network Access Account (NAA) in System Center Configuration Manager 2012 Beta 2 if you are deploying operating systems with it. Windows Pre-Execution (WinPE) needs an account to access content on the distribution point. In order to set the network access account, open the SCCM console and navigate to this node: AdministrationOverviewSite OperationsSites. Right-click on the SCCM site in the right-hand pane, and select Software Distribution. Click on the Network Access Account tab, and set the account you want to use.