Installing Ubuntu on external hard disk
I have a computer with windows 7 installed. I'm sharing it with other people that don't accept a boot screen where you choose between windows and ubuntu, but I want to be able to run ubuntu from an internal drive. Is there a way for me to install ubuntu on a HDD partition without tampering with the existing boot procedure at all, and having a bootable USB thumb-drive that lets me boot up ubuntu?
Please take into consideration that it's not an option to first install ubuntu and then restoring the MBR from some sort of backup, since the other users of the computer in question are quite paranoid.