Nah, screw it up. Best way to learn.

If you can get an external drive it is nice to have an install that can't hurt you that you can play with. This will work with an external as long as you can turn off the internal drive.

Right now I am on my test platform (spend most of my time here) running 10.04. My internal drives are "off" so that there is no way I can screw up my "real" installs.

I learned about multi booting the first week I had Hardy (first linux) installed bucause I have an unreasonable wife.

I broke Hardy past my ablity to fix it 5 time s the first week playing with it. It was so FUN. The wife was not amused. She thinks the computer should work.

I installed a second Hardy just to experiment on. Did nothing to the "main" until it past the second install and that included updates.

Still have that first Hardy on here too. Works great.