I tried all this and got a Windows Boot Manager "System Error - 0x0000017" Unknown error or something. Have you come across this yet? Just learned an important lesson. MS changes things in each build, so using the winpe.wim from the WAIK will not be all that compatible with say July CTP build 5472. I know, derrr, I'm stupid but i guess it did teach me a fair bit. - Also, if anyone is having trouble copying over the .dll's because of write protection/system errors, - try MOVING all the .dll's from the boot.wim to another dir (called backups). - - Next copy the required .dll's from the install.wim to the boot.wim. - - Then MOVE the .dll's from the backups dir and DO NOT OVERWRITE (this is the reverse workaround). - - Hold shift and click "No" for effectively a "No to All" type action. - - This should only have added 10-15 files to you boot.wim Continue as per instructions above.