Intel Core 2's Are They All 64 bit ???

Yes, they are all 64-bit capable.

edit - but they all also support 32-bit. They do both.

They are 64bit. I have vista x64 and it run excellent with pure 64bit apps. But i wouldn't recommend the vista x64bit if you are a gamer and if you don't have a good reason to go 64bit. Only reason maybe you would go for 64bit is for the security and you have over 2-3gb of ram and a pretty decent machine.

OK so if they are all 64 bit but support both 32 + 64 bit software, does that also include the operating system? (ie i can go ahead and install my lovely Vista Ultimate - but 32 bit version upgrade on to a new built Core 2 system ? ? Or is the support for software only limited to applications running under the OS (in which case i gotta buy another Vista 64 bit from my mate Bill G!!!) 8O

why not? according to MS, 64-bit versions are for gamers. I'm running 64-bit Vista and never have looked back. Unless you're looking to play REAL old games then you are fine. WOW, GTR2, Half-life 2, Half-life 1, DOOM3, UT 2004 has been running w/o a hitch at 1920x1080 resolution on a G8800GTX for the last two month. Have not had any BSODs.

also, 32-bit SW with 16-bit extensions and 64-bit OS not ok, and 16-bit SW and 64-bit OS not ok.

not to much of a factor with modern software, but there is a bit of older software that while it says 32-bit, still utilize 16-bit extensions. these will NOT work in 64. I however doubt this is much of a problem with a good deal of Toms users, but it still exists. :wink:

as Jack said, normal 32-bit programs and 64-bit programs will work (usually) fine under 64, but 64-bit programs (all 2 of em :twisted: ) will NOT work on 32-bit Vista

Core Duo (the original one) is 32-bit
Core 2 Duo is 64-bit (and so are Pentium E and Celerons based on Core 2 microarch)

I'll also add that while it is true that there are no longer many 16-bit programs, there are supposedly still installers for 32-bit programs that are still 16-bit, which is unintuitive and annoying. I haven't bothered going 64-bit yet so I don't have personal experience, but that's what I've heard.

OK guys thanx for the great info - especially jumping jack + alaskafox. So means i can go build my new intel Core 2 system with the vista 32 bit OS i already bought and i probably (by accident not design) got the best compromise options of cpu with operating system at the moment    

It'll probably be a couple years before some software you just gotta have comes along in 64-bit only. The transition from 16-bit to 32-bit took years, and that was far more needed by the average user than the 32-bit to 64-bit transition. With all the legacy hardware out there, I suspect most of the more popular software will be offered in 32 and 64 bit flavors for some years to come.