I just found a few links on adding the Integration Components to WinPE. Why would you want to do this? Simple; say you want to deploy operating systems to VM’s via SCCM, WDS or ImageX. There’s a lot more tools out there that will use a WinPE boot image too. You will need drivers, especially for the NIC to work. To get those, you’ll need the Integration Components. Mike Sterling has documented the process.
Credit: Mike Sterling.
EDIT:
Mike has updated the script that he used in the original post.