Hello there...

I am buying a new PC and would like to know if Intel Pentium D and Intel Pentium 4 Extreme Edition are supporting feature Windows XP 64 and Windows Vista Operating systems...
For now I can run Windows XP on it but since the days of XP64 and Vista are comming I would also like to be able to run it on my new system.
Both CPUs are supporting Intel® Extended Memory 64 Technology that "Provides flexibility for future applications that support both 32-bit and 64-bit computing" but I would like to know what this really means... and if Vista and XP64 are really going to run on this CPUs...

Thanks,
-Andrej

To answer your questions:

Yes both of these CPU's are EMT64 ready, meaning they will support the newest 64-bit OS's, both Windows XP (64-bit Edition) and Windows Vista. These CPU's are also backwards compatible to 32-bit OS's like the standard Windows XP (Home/Pro).

In fact I'm going to be purchasing the latest AMD Athlon 64-X2 and I'll be running a dual-boot config, one with XP Pro(32-bit) and the other XP Pro(64-bit).

Also note that there should be no reason you couldn't also run any of the 64-bit *nix distros either

You shouldn't worry too much about Vista, as it will still support 32-Bit CPUs. Microsoft is not crazy enough to immediately assume that EVERYONE will suddenly throw out their computers and go buy brand spankin' new 64-Bit systems.