Since both the x86 and x64 versions of Vista are on the same DVD, will the installer determine what kind of processor is in the computer before copying files? Or will I need to purchase both an x86 and x64 disk for the two computers I'd like to install Vista on? What I'd like to be able to do is purchase a single DVD and install Home Premium on both my Athlon 64 X2 machine (x64) and Pentium III-S machine (x86). Since MS lets us use the DVD three times before requiring us to purchase a second product key, this shouldn't be a problem, right? My Super P3: Pentium III-S 1.4GHz @ 1.58GHz, 512K L2 X800XT All-in-wonder, overclocked to 580/600. 250GB HD 2 gigs of PC2100 RAM QDI Advance 12 mobo, this baby rocks! SB Audigy 2

You do realize that Vista is slower than XP, right? I recommend you read the post just below your's....

The product keys are not interchangable across board - so you only get to install the version of Vista that you paid for. How To Ask Questions The Smart Way

The key type will determine what you have bought a licence to use !

If you want a x64 OS get XP x64. AMD Athlon 64 X2 4600+ OC 2.7ghz 2GB Dual Channel DDR 3200 Nvidia 7900GT SATA II 2x 300gig 7200rpm 16mb cache RAID-0+1 Gigabyte Nforce 4 SLI

I know it's slower, but XP was slower than Win98/2K when it first came out, and for the same reason: immature drivers. It eventually got just as fast. :) I'm confident Vista will do the same. Crap. I guess I'll be buying 2 different versions then. M$ is really tempting me to P2P, but I won't! I'm strong! I think. :) My Super P3: Pentium III-S 1.4GHz @ 1.58GHz, 512K L2 X800XT All-in-wonder, overclocked to 580/600. 250GB HD 2 gigs of PC2100 RAM QDI Advance 12 mobo, this baby rocks! SB Audigy 2

There might well be improvements but I suspect immature hardware would be a major speed limiter to Vista. Modern OS's are usually written around modern machines. There's nothing new in this. Many years ago I tried putting W95 on an old 486 from the Win 31 era and it was horribly slow. DerekW