I know there is a user here who says there is nothing wrong with Vista, but sorry to say, it just plain blows

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But I will back it up with reasons why. Put it this way, vista is the Windows Millenium. Lets hope they release another Windows OS to replace Vista.
I tried Vista on a dual core 3800+ AMD cpu, 2gb dual channel ram, and Sli'd Geforce 7600 gt video cards... With those specs, Vista is "usable" not fast, but usable.... After playing a single game of quake 4, all of the 2gb was nearly filled of the ram.
Another thing I disliked was the fact that when I wanted to simply find one thing on Vista, it seemed like you had to click literally through tons of options before it brought you to it, whereas on XP, you click Start/Settings/Control Panel.
You do not get a performance gain if you install Vista. Heck, i use the 32-bit version of windows xp pro on my dual core 4200+ setup. Reason why 64 bit is not on here because it makes 0 difference when I run and play my games. Maybe for some, but the ones I care to play, it made the same exact FPS.
To me, XP is definately one to stick with and use. If im forced out of XP, then im jumping right in to Ubuntu Linux, no questions asked. :-)