Hey there,
First of all, you can turn the UAC (user account control) off by going to the Start Menu > Control Panel, double-click "User Accounts", click "Turn User Account Control on or off" (you'll have to go through that thing one more time
). Uncheck the box and click OK. Looks like you'll have to restart before it goes in effect. Hope that helps with that part.
I triple boot Ubuntu, Vista, and XP. I use GRUB as the main bootloader. When I select Windows, it uses the chainloader to allow me to select between XP or Vista. I find I spend 50/50 of my time in Vista and Ubuntu, so XP is just there just because.
Vista does have DX10, assuming you're a gamer. I really haven't had any issues.
Oh, another thing you can do is go to Start > Control Panel, double click "Programs and Features", then click "Turn Windows Features on or off". By default, tablet PC services are turned on. You probably don't need that (unless, of course, you actually have a tablet...don't believe that model is, but I'm not familiar with it). Also in the Control Panel, is "Performance Information and Tools". There are some useful things in there. Try playing around with that stuff and report back
Oh, one more thing: Make sure you're in "Classic View" in the control panel. You'll see that towards the top left of the Control Panel window once you open it. Then, the preceding instructions should make more sense.
Hope that helps.
