Running an OS from External Hard Drive

I've been wanting to install an OS on my external hard drive because my internal drive gets hot and has been acting a little funky lately. Is there absolutely any way at all to do this without basically taking apart my computer and connecting everything as if it was internal? I've heard of "USB booting" and I don't know if it's feasible. I don't care if I actually have to make an initial connect with my internal drive before booting into my external, I just want to be running a new, fresh OS off of a true external hard drive.

I've heard that Fedora and Ubuntu can be booted from a USB, but nothing is retainable, it's just more a test drive for the OS. I want a true OS. Windows, Mac, or Ubuntu preferably.

Thanks for any help!

 

Possible?

 

Maybe this can get you started. Everything should be retainable.

http://www.novell.com/communities/n...b-bootable-linux-hard-drive-without-dual-boot

http://ubuntuforums.org/showthread.php?t=1471253

Also, you can go to Youtube and do a search of

installing linux on bootable external hard drive

There are a number of videos explaining the process.

 

There is no problem installing an OS on external HDDs but the transfer rate of USB ports is much slower than internal HDDs so do not expect the same performance.

I know you said you you don't want to open your PC but it is a simple job to put in an extra HDD and you will be able to boot much faster from it.
Check out this video.

http://www.youtube.com/watch?v=vnEga6ga5hM