I’ve run RedHat and Ubuntu on a Virtual PC 2007. I think Ubuntu is probably easier. However, unlike the 20 or 30 minutes it takes to install a Microsoft OS on a virtual machine, Linux systems seem to take way longer and go through several strange graphics screen gyrations. I actually did a re-install of Ubuntu about a week and a half ago, after 15 minutes of occasionally asking me about preferences, the machine just sat there and loaded byte after byte (with a blank screen) for about 4 hours before it completed. After the exceedingly long install, the system boots fine and is as fast as any Microsoft system.
I have never seen a functioning Linux distro on any of my machines take longer than 30 minutes...most under 15 minutes...
AM 2 and above sockets with X2 up to X6 processors.