Dream, sometimes it did matter as part of everything, and many times it didn't.

Lately, I try Windows 3 versions that I did not any familiar with them.

First one, the most famous, talk of the town Windows Vista Ultimate: and I think as if it just something that nothing than an interface change OS from XP, many drivers and what else?

After a long while, you still do need driver? Better let tomorrow tell.

Second, Windows XP x64 (64 bit edition), I think that this one is the best among all three (that I tested), the only problem that I've seen…. Compatible.

Antivirus cannot be used, interface Change cannot be used. For all other such as stability, workable, speed all better than its 32 bit ancestors.
So please, Antivirus company please release all 64 bit out.

Third, Windows Vista Ultimate x64, one that be compromising about interface and stability. Way that its look and feel and the performance quite better than both above, only problems like other x64 Windows: Program compatibilities.

For all of problem hereby I wait to see new programs that can run smooth in x64 version. Hope I can see them soon.