MSCOMM32.OCX and error 339

This control is for control of serial port in VB6. I get an error 339
and MSCOMM32 missing or not registered. I have registered in regsvr32
and it does not help.
The application does work if installed in the system as it comes from
the factory but after adding many programs it now no longer works. I
d9n't understand how other applications can make this fail. All of
these applications are on my XP system with no -problem.
The laptop does not have a serial port but that should not be the
problem since it does work when in an out of the box state. I have way
too many ap0licatioisn to try install one by one to see when this
starts. There has to be another way!