If you’ve got a 64 bit PC or are thinking about buying one, and are considering installing any of the versions of Windows for x64 then you should probably read this article (though if you’ve been thinking seriously about it you probably know most of what it says).
For those of you who haven’t looked into it, one major problem area for x64 users will be driver support. You can’t use 32 bit drivers on a 64 bit system. And, since x64 is relatively new, driver support is weak. As with any version of Windows there is built-in support for many of the most popular legacy devices, but as you probably also remember if you upgraded from 98 to XP, many of those peripherals we depend on just won’t be supported, not now, and maybe not ever. And with many software packages increasingly using software drivers as part of their design (anti-virus, monitoring, utilities, etc.), you’ll similarly be seeing some of the software you rely upon not working, despite x64s WOW (Windows on Windows) 32 bit subsystem (I’m not 100% sure about this statement, pretty sure, but I could be wrong). If you’re thinking about it just make sure that the peripherals and software upon which you depend are supported before upgrading.