Originally Posted by jetboy623
LOL, I know. Trust me, I use Linux all the time (On my general-purpose laptop). I meant if he were to install multiple versions of windows on the Hard drive.
in which case the registry still doesnt matter what so ever becaues the windows registry is generated from the registry hive files in \\Windows\\System32\\config every time you boot the computer, meaning that different hive files are used for each installation... and all you REALLY have to do for multiple versions of windows would be edit your boot.ini to include the extra entries... HOWEVER, it would probably just be easier to use grub cause it kicks ass
OP: it should just be like a normal install set up
just make sure you write grub to the MBR of your external drive, and then have your linux os's partitioned correctly and grub (installed to the mbr of your external) configured correctly
after that, you just set your computer to boot from usb, and when your computer finishes its post it should hand it over to the first boot device (being your external) at which time grub runs and you see all the goodies you have grub entries for
one draw back though, is with this sort of set up, you wont be able to boot OS's existing on the computer... but you CAN make a grub entry to pass to the next boot device which would allow you to do this
ive seen it done on many live cd's but cant think of how to do it myself