How can I make the keyboard layout selection apply to all windows, not just the current window?

Hello,

I use the Dvorak keyboard layout, and my wife uses the standard U.S. layout.  We just got a new computer with Windows Vista, and we want to share one user account, but be able to switch between the two keyboard layouts. 

I have already gone to Control Panel > Regional and Language Options > Keyboards and Languages > Change Keyboards, and on this page both "US" and "United States - Dvorak" are listed, with "US" set as the default.  I have found that I can use the language bar to select US or US-Dvorak at any time, which seems perfect at first glance. 

But the problem is that if I select US-Dvorak while I am using one program (e.g., a web browser), and then later I switch to another program (e.g., Notepad), then the keyboard layout reverts back to US.  Essentially, I have to re-select US-Dvorak every time I launch a new program or switch to a new window, which is quite annoying.

How can I easily switch between US and US-Dvorak keyboard layouts, in such a way that once I select a layout, that layout takes effect for all windows, not just the current window?  I want to be able to select the keyboard layout one time, and have that selection stay in effect until I make a different selection.  I know from experience that this can be done very easily on a Macintosh or in Ubuntu Linux, so surely it can be done in Windows Vista, right??

(By the way, I know that I could solve this problem by creating separate user accounts for myself and for my wife, with each user account having a different default keyboard layout.  But we simply don't want to do that.)

Paul