Have finally fixed this [touch wood] - eventually found a forum entry that stated that a release of the Giga R1 boards came out with either incorrect or no firmwear installed!!!!!!
On 2 seperate boards I had 2 different issues.
Windows 11 OS.
1: Both boards not showing as any form of USB device.
2: Eventually ???? was able to see a DFU appearance which allowed me to update firmwear..
Windows 10 OS.
Was very unstable - dropping COM ports and not compiling ANY Giga examples.
Am currently programming and compiling OK on W11 which is most required so here's hoping..
Regards Colin.