Ah, but what if one your clients needs to use, let us say, Excel...

My mistakes with the training course code would have been fixed if the company would have bought Excel licenses fof our customer workstations.

And I just remembered it was DDE (dynamic data exchange), not OLE. OLE was much better specced than DDE. Like I said, it was way back when. But the basic rule (don't test using both a home-grown client and server) still applies.