From what I heard, you only get 2 installs with the key that comes with the cd.After that you're shit out of luck if you need to reinstall vista.Gates expects you to shell out a few bills more for a new license key.And the last beta version of Vista looked slick, but was nothing but a resource WHORE in my opinion.I have 2gigs of ram and a athlon64X2 dual core CPU and vista sucked up 25% of my ram and 15% of my CPU just running the desktop and my normal startup programs like antivirus and firewall.
XP Pro uses less than 8% of my CPU for the same situation and about 8% of my ram.