Portable HDD Install, Architecture Matters?

[jinba.ittai]

I want to install operating systems on my 320gb hard drive so that i may boot from usb on other computers. My question before i start is, if i install a operating system on the hard drive from my AMD (64 bit) processor onto the portable hard drive, will i be able to boot up from another pc, say for example another pc that has an Intel processor?

I will be installing only 32 bit operating systems, i was just unsure about the different cores of systems ill be booting from. Also, if i have applications installed from that boot on the portable hdd that were installed from the AMD machine (booted from portable hdd) will i have to reinstall them when i boot from an intel machine?

Or does this only change when going from 32-64 bit systems? (sorry if im confusing you, i cant elaborate any clearer.)

Also, shoould i encrypt the drive before or after installation of an operating system?

[jinba.ittai]

Well i tried to install, and messed up the grub on my system. Should have unplugged my 2 hdds in the system before trying to install from live cd to a portable hdd. Fail, someone wannna point me in the right direction of fixing grub?



PS. My system has two hard drives, one with Windows 7 and the other with ubuntu 10.04, how do i fix grub without damaging eitehr?