I was struggling on XP 32 bit, trying to edit video.. Maxxed out the ram, and premiere just choked.. Crashes.. sluggish behavior -- a real nightmare. uI heard you needed expensive video cards, etc to get a good video editing computer... Due to tight finances, I decided to test my 3GHz Dell Intel Core2Duo with Vista 64...
Still ran sluggish, video editing was still a grind... So right when I thought perhaps "they" were right, and I needed a $3000 workstation video card, I decided to try out a ton of ram.. I bought 8GB, and VOILA! Real time editing in premiere -- effects and everything... You don't need to render the timeline to see your work, and it runs absolutely stable like a dream... better than my MAC!
The ONLY drivers I can't find are for an HP Color Laserjet 1500, and a Logitech Webcam... No biggie there. Vista runs flawlessly, and you'll be really happy on it.
Moral of the story? You can't use more than 4gb ram on a 32 bit OS, (really no more than 3.6GB) and moving to 64-Bit OS makes the ram wide open... Add as much as you can afford, and enjoy editing video swiftly... forget the expensive video cards... Ram is cheaper.
-PK