WMI or other technique to obtain window list on remote computer

I'm successfully using WMI to obtain lists of all processes, services, and hardware/os information from all computers in the domain.

What I'd like to do is get a list of all windows on a workstation along with their handle, caption, etc. just like Spy++ gives you. I thought WMI's Win32_Thread class would do it, but it doesn't. Does anyone have any ideas of how I can get a list of windows on remote machines similary to Spy++ ?

Here's a little more background on why I'm doing this. We have a software application that runs on all of the machines in the building. The program I've written allows a user to kill the process on all the workstations its running on (say it's 10:00pm and a backup needs to be done - this will close all the open database tables).

There are certain processes that should not be killed. I can discern what they are by examining the windows caption. If a process has a thread with a specific caption, I would not allow the operator to kill that process remotely. But WMI doesn't yield this information, that I can see.

Thanks!

Scott