I have windows 7 on a partition of my harddisk and ubuntu 12.04 on a partition of a external HDD. Dual boot is working fine. Both systems are working fine. Can I boot with my external HDD with my ubuntu ? ( ex: on another PC ? ) When i try to boot from the external HDD is not working ? The only way i can boot ubuntu is from the normal boot menu choosing a option. thanks
Because when You installed Ubuntu on external drive You selected to install bootloader on harddisk.
My solution is: reinstall Ubuntu on external drive and make sure u select external drive when You select bootloader location(This is in partitioning tab).