Generating a new WinPE Boot Image is done via a command line utility. This utility requires you to have administrator rightson the machine where you run the tool. The reason for this is that it mounts registry hives from the offline media, a privilege that requires administrative rights. In a locked down environment this can be done on a standalone non domain joined computer.
Creating of Windows 7SP1/8/8.1/81. Update(s) version of WinPE is described in this document. For issues when generating access for Windows 7 versions of WinPE please email email@example.com.
Note:Windows8/8.1/8.1 Update 1 versions can still use Windows 7 version of BranchCache hashes. Read the sections around hash and cache in WinPE in this document.Windows 7 SP1 cannot use Windows 8 hashes.
The WinPE images created are then used as regular boot images in ConfigMgr or MDT, there is no difference to them except that they have BranchCache enabled.
Figure 1shows WinPE images that have been enabled with BranchCache imported into ConfigMgr, ready for use.
The tool to create the BranchCache enabled images is a command line tool as shown below, the reason for this is that we know some people will want to automate this.
Figure 2 shows the default output from the command line if no variables are fed to the generator.
WinPE Generator Command Line Options
The generator has the following options:
"Source.wim" – Is the full path and name of the OS source .wim file to use to get resource data.
Index – Is the index number of the source.wim to use, Professional or Enteprise.
"Boot.wim" – This is the full path and name of an existing WinPE boot WIM file
Index – Is the index number of the WinPE image to modify.
The following options can also be provided:
/Add-iPXE - Adds iPXE Boot Loaders for WDS & ConfigMgr PSP Integration
/Add-BITS - Adds BITS For Bandwidth Policy Aware Downloads in WinPE
/Copy-BITSPolicy - Copies the local BITS policy into the WinPE Image, This overwrites the default BITS policy which is limited to 1Mb/s during business hours of Monday-Friday 8-17 and 2Mb/s during any other time. Ignoring speed limits on the local LAN = Full throttle for cached content. Use GPEdit to create a local BITS policy and this will then be copied automatically at build time.
Note: Boot wim file will be modified, so ensure you have a backup!
Note: Source.wim MUST BE ENTERPRISE unless using /Add-BITS option!
Note: Index is the index number of the wim to use
Note: /iPXE switched is to be avoided until further notice. Honestly, don’t touch it.