This post is directly prompted by an email I received from Paul letting me know about a utility he'd learned about from other Exchange MVPs. So thanks to Paul, Jim, and Jeff!
When Microsoft first announced that Exchange 2007 would run on 64-bit hardware only, lots of people immediately started to point out (with varying amounts of glee, depending on who they worked for) that this would inevitably make Exchange 2007 a horribly expensive upgrade. Microsoft's counter-argument can be summed up as, "Relax. If you've been buying hardware at all recently, you're already buying 64-bit capable hardware." Now, in all fairness, this is probably true, but the question then becomes, "How can I be sure this hardware is 64-bit capable?" The answer is: that depends.
I've found that it's a lot easier to tell whether your server hardware is 64-bit capable or not if it's running AMD processors. Both the Opteron and Athlon 64 lines will self-identify to Windows, which means that a simple check of the Property sheet of My Computer will tell you:
My Computer on an Athlon 64 processor -- ready for Exchange 2007
Intel processors are a different story. If it's an Itanium, of course, you know it's 64-bit, but you also know it's not compatible with Exchange 2007. That leaves the Xeon and Pentium lines. Instead of clearly labelling the specific processor models as being 64-bit, Intel merely added the Extended Memory 64 Technology (EM64T) extensions to them. The presence (or absence) of these extensions doesn't show up in My Computer:
My Computer on an Intel 32-bit processor -- and still in the dark
My Computer on an Intel 64-bit processor -- and still in the dark
Instead, you can use the free utility CPU-Z, which will tell you all sorts of information about your CPU. Most importantly, though, it will let you easily see whether you're running a 64-bit system:
CPU-Z on an Athlon 64 processor -- ready for Exchange 2007!
CPU-Z on an Intel 32-bit processor -- no Exchange 2007 for you!
CPU-Z on an Intel 64-bit processor -- ready for Exchange 2007!