F1 is not bringing up help in my application.

It works on my development PC, but not when I install onto a test PC.

Using http://fox.wikis.com/wc.dll?Wiki~VFP7RuntimeFiles~VFP as a guide:

These files are installed in the application folder:
foxhhelp7.exe
foxhhelpps7.dll.

Foxhhelp7.exe is registered.

Yet when F1 is pressed, nothing happens.

I also tried putting then in the SYSTEM32 folder, but it made no difference.

Is anything else needed to get F1 to work?

(I can double-click the CHM file and it opens fine).

Note: I used Installaware to install the application. It installs these merge modules: Vfp7Runtime.msm and MSVCR70.msm.
I then also manually ask it to install foxhhelp7.exe and foxhhelpps7.dll into the application folder, and to register foxhhelp7.exe.

Any suggestions on what to try to get F1 help to work?

Thanks
Cyril