Windows on an iMac: unable to change keyboard layouts I dual boot Windows 7 and MacOS X on my iMac. 

Recently I needed to type some text in a non-English keyboard layout in Windows. I installed the second keyboard layout the way I usually do, but when I pressed Alt-Shift to switch, nothing happened. After playing around with the settings a bit more, I was able to switch to the other keyboard layout, but not back to the regular American English layout. No language bar either.

alt+shift does not work, nor does Ctrl+shift, nor does specifying a separate key combination for each layout like Ctrl+0 | Ctrl+1 | Ctrl+shift+0

Interestingly, the Text Services and Input Languages dialog box dies with I select the United States (Apple) layout and click on Properties. 

I am running W7 64-bit on an 20" early 2009 iMac. I have the version of the wired, USB Mac keyboard without the keypad and the middle group of keys. Bootcamp is up to date.

Update

I did a bit more troubleshooting and discovered that for some reason, ctfmon.exe, which I believe is the process that handles switching between keyboard layouts and displaying the language bar, isn't running. I also encountered several other posts on the Net with people complaining of similar issues when running Windows under Bootcamp, but unfortunately no solution. 

Anyway, trying to run ctfmon.exe manually (from the start menu or Run dialog) or adding it to the Run section in the registry does not fix the isssue because ctfmon.exe simply refuses to run.
I had this problem and fixed it by: Control Panel -> Regional Settings -> Keyboard and Languages (tab) -> Change keyboards (button) -> Selelct the top language added: (English United States) -> then click "Add" -> Navigate between the options to (English United States) -> click on "keyboard" -> now check the option "US"

This solved my problem, I hope it solves yours