:tard:  Actually, you can edit the registry without using ERD..  At least, I have no problem doing so with WinPE. All you need to do is run regedit, and then select HKLM.  You can then go to file and load hive.  Browse to C:\Windows\System32\Config\.  You'll see files named System, Software, etc.  Select the one you wanna modify and call it whatever you want (like Local_Software).  Then modify the hive you've loaded, be sure to unload it and you're done.