Hands down, the best way to screw around with Linux or any new OS without harming anything else is to download VMWare Player and an image of the distro you want to try. You can also still be messing around and looking up commands in Windows at the same time this way. The LiveCD is also a good option, but then you can't minimize Linux.
I tested out Asterisk and some experimental Windows setups using VMWare.
Regarding the PVR thing, I'd recommend looking into either KnoppMyth or LinuxMCE, KnoppMyth is a Debian-based distro, originally based on Knoppix, but it's pretty straight-forward. As for LinuxMCE, it's basically an extended version of Mythbuntu that's supposed to be stupidly simple to get up and running since it's still Ubuntu-based.
As for Windows, well.. if you're not a PC gamer you can live without it. Good luck with making the switch. The only other advice I can offer is that you should never, ever make the default runlevel 6.
Thanks!
I downloaded the VMPlayer, perhaps I'll get to play with it tomorrow.
I need a new video card to take advantage of my new 22" LCD, I think I'll get one with a TV tuner to try Myth TV.
I'm running Mepis (mainly) I can also boot Kububtu and 64 bit XP professional.
At one time my computer ran 5 operating systems and Window$.