We have at work a few dozen of laptops and some desktops that have the same GUID. After adding the bannedguids registry key I was able to pxe boot, it loads the boot.sdi file and winpe.wim file and it gets stuck on the winpe 4.0 welcome screen and those dots which were supposed to rotate in order to show that the winpe is loading, do not appear at all. The hardware is windows 8 compatible, because I have tried to install windows 8 from a dvd media and I have succeded to do so without any troubles. I have deployed one task sequence to the all systems collection and I have removed the registry key and I get the same "error". So, I made a winpe 4 bootable cd from ADK, using this guide http://social.technet.microsoft.com/Forums/en-US/bc9b8da6-6210-4e47-a997-e5f2d1c3113d/bannedguid-in-sccm-2012-sp1-system-center-configuration-manager-2012-sp1 and surprise, winpe loads. So, I thought then that is a problem with the drivers which I have included in the boot images. Then, I have tried to build a boot image from scratch, which I managed using this guide http://myitforum.com/myitforumwp/2013/08/01/how-to-create-configmgr-2012-boot-images-from-scratch/ I added it in SCCM, I have distributed it, I have added it to a task sequence that I have deployed to all system collection, but I got the same result. Those spinning dots fail to appear. Even if I added the optional components available to WinPE, I still got the same result.
Any help and/or ideas will be greatly appreciated..