I just found PDR 6739 which describes exactly my problem:

Using Xbase++ 2.0 the class method
AutomationObject():isInstalled( cProgId | cClassId )
does not properly detect a COM/AcitveX object when a ProgId was
passed as
parameter.

Append the ProgId with Chr(0) as shown in the code below:

========================== snip ===========================
#pragma library( "ascom10.lib" )
PROCEDURE Main()
   LOCAL cProgId := "Word.Application"

   #define WORKAROUND_6739
   #ifdef WORKAROUND_6739
   cProgId += Chr(0)
   #endif

   ? AutomationObject():IsInstalled( cProgId )

RETURN
========================== snap ===========================

-- 
Met vriendelijke groet,
With kind regards,

Rens Zwanenburg

Hi Chris,

I tested this on a single machine (Win7 pro), I build two versions of the same application (with both xBase 1.9 and xBase 2.0 environments).

When I start the 1.9 version everything works just fine (return value from :isInstalled() == .T.); but when I start the 2.0 version the return value is always .F. ??

-- 
Met vriendelijke groet,
With kind regards,

Rens Zwanenburg

Op 9-5-2016 om 23:34 schreef Chris Chambers:

On 5/9/2016 7:32 AM, R.M. Meijer wrote:

Hi,

Within an XBase 2.0 application I call
AutomationObject():isInstalled(CLSID) and I always get *.F.* as return
value?

_Sample:_
AutomationObject():isInstalled("TIS.TX.TextControl.19")

With XBase 1.9 this method works fine!


--
Met vriendelijke groet,
With kind regards,

Rens Zwanenburg

Hi,
Is the active X control properly registered, if you are using two different machines for 1.9 and 2.0
Regards
Chris