The only thing I can suggest is download the Symantec "Prep" Tool.........
I believe the file you are talking about is called rnav.exe and is available here: _http://service2.symantec.com/SUPPORT/nav.nsf/8d071816eedd7cac88256c0e005a96e5/33497f6e8a319ece88256ace0076cc02/$FILE/Rnav.exe
Let me know if it works for you. i had the same problem with most of the beta's and couldnt fix it