I tried to install Vista Beta 1 on a separate partition in a Toshiba Satelite 5100 and it failed to complete, so I decided to let it install on c:\ and it did fine. Seems to work fine, including the Ethernet port. But, no drivers there to recognize the dial up modem. But then, that's always been a proprietary Toshiba software driver.
So far it works fine, and I'm wondering what makes it more "fun" than XP.
