SQL Server 2008 Management Studio Express on XP64?

The installer for SQL Server 2008 Management Studio Express is not matching the instructions, which is disabling me from installing it.

As you can see in the 2nd screenshot here http://www.404techsupport.com/2009/08/19/microsoft-sql-server-2008-management-studio-express-stand-alone/

This screen is supposed to have a “Management Tools – Basic” checkbox option:



I can’t get past that screen because the only option I’m getting is:

I’ve tried installing both the x86 and the x64 installer, with the same roadblock.

Here’s what I’m running, if that helps:

System:
Microsoft Windows XP
Professional x64 Edition
Version 2003
Service Pack 2

Computer:
Intel Xeon CPU
5140 @ 2.33GHz
2.33 GHz, 4.00 GB of RAM

Thanks in advance for any help you might be able to provide with this.
-Cori