Vista was incomplete upon release, the eye-candy only worked on new systems.
As for depending on M$ Service Packs for drivers... don't count on it, especially on the 64-bit OS on laptops/notebooks (don't try it and on a HP laptop it just won't work)
Vista had all the right intentions in terms of added value to purchase the new OS, but incompatibilities surfaced out the waszu...
M$ released it to make a buck, then fixed it based on user feedback and released Win7 to capture your other buck.
Win7 is well built, Vista should never have gone to market..
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