Just an update ... all now working as advertised!!
How so??? ...
Procedure for anyone else so affected - but I make no claims for expertise. The following is what I did -
1. Start - Run... - type:msconfig, enter
2. On the Start list deselect any Bluetooth listings
3. In the start 'Search' box, type 'ms services'
4. Select the resulting listing and find Bluetooth entries and deselect them.
5 Now you can install the Widcom drivers and plug in the Bluetooth adaptor. complete the installation and
IGNORE the Windows error warnings.
6. Restart when ready and Robert is your Dad's brother!!!
It has worked for me but, as the self-admittedly least sharp axe in the woodshed, there may be better, more technically savvy ways of doing it.
HTH