Install ubuntu on windows and mac with an external hdd

[Armaan_11]

I want to install & run ubuntu (or windows) on an external hdd. When I plug it into a mac it should work and when I plug it into a window it should also work. Can someone guide me through this or tell me if this is possible?

 

[nightcap965]

Papa Google, he say: http://ubuntuforums.org/showthread.php?t=1065670

 

[Gjwilly]

When I plug it into a mac it should work and when I plug it into a window it should also work.

You'll have a problem with installing Windows 8 and above because every time you switch between a Mac and a PC, Windows will detect the hardware change and deactivate itself.
You'll have a different problem with Windows 7 and earlier because of EFI vs Legacy boot loaders on the Mac.
Stick with Ubuntu.