Dear Mike,

If your form is functioning on another machine as it was working at first in your client machine without problem, then as you think, something has been happened on their computer.

As you know comctl32.ocx is normally in "system32" folder, if I was you, I tried to make a test app to use progress bar on a form and test it on the machine to see the same action or its functioning. Tracing without possibility to watch footsteps is sometimes so hard.

I'll follow up the thread to hear about fixing method.

Good luck,
Farhad