Unless you’re working with ridiculously huge Excel files, or prefer the bleeding edge to practical utility, go with the 32-bit version.
The Office 2010 retail disc comes with both 32-bit and 64-bit versions. Obviously, you can only install the 32-bit Office into a 32-bit version of Windows. But even in Windows 7 x64, the installation program defaults to the 32-bit version.
Believe it or not, that makes sense. There is very little reason to use Office x64, and a very good argument for sticking with the older architecture.
The big problem is add-ons–those third-party programs that make Microsoft Office a better suite than it would otherwise be. These programs, which will all work in the 32-bit version of Office running in the 64-bit version of Windows, must be rewritten to work in the 64-bit version of Office.
As I write this, a good many add-ons have been rewritten for the 64-bit version of Office 2010, but not all of them. Out of five add-ins I just checked, three of them (Office Tab, Search Commands, and Classic Menu) support 64-bit versions of Office–usually with a separate download. The other two, ASAP Utilities and CrossEyes, do not yet do so.
So what advantages do you get with the 64-bit version of Office? You can create a 2GB Excel spreadsheet. For must people, this simply isn’t an issue.
Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at answer@pcworld.com, or post them to a community of helpful folks on the PCW Answer Line forum. Follow Lincoln on Twitter, or subscribe to the Answer Line newsletter, e-mailed weekly.