kof94 is right you will extract the boot sector with UltraIso or whatever program you wish, and rename it to (Vista.DAT) or whatever you wish. Now you must follow the Longhorn guide by renaming your BOOT folder to CDSH etc. One more thing once the VISTA (all in one disc) is Optimized it will fit on a 4.7GB DVD if both Install.wim files contain x86 & x64 of Vista. SO there for you fit all versions of Windows on one 8.5 DVD, as I have succeeded in this. My disc contains both x86 and x64 Vista, 4 versions of XP, 4 versions of 2003, 4 versions of 2000, 4 versions of NT, and all of the Windows 9x. Now the MSDN version of Vista contains the RTM versions of Vista which supposedly contains less drivers than the Retail Version of Vista. So if you own a retail version of Vista you can use Chon’s method of modifying both of the x86 & x64 install.wim files to contain HOME BASIC x86 & x64, HOME PREMIUM x86 & x64, Business x86 & x64, and Ultimate x86 & x64 then replacing each install.wim file in your sources folders. This enables both versions to load x86 & x64, and furthermore enables you to optimize the Vista portion of the image even smaller. Like I said before in another post you need both x86 & x64 boot.wim if you ever need to make a recovery. You cannot recover or fix an x64 system with an x86 loader or vice versa.