Thanks for further replies -
My pc is : Chillblast Fusion Ninja 18749, bought in Nov 2008 with basic relevant specs, as quoted in original sale docs, as follows:
Intel Core 2 Duo E8600 Processor (3.33Ghz)
Asus P5K-SE/EPU Motherboard
GeForce 9800 GTX 512MB Graphics Card *** Replaced a couple of years ago with NVIDIA GeForce 210
500W Power Supply
4GB PC2-6400 DDR2 Memory
20x DVD-RW Optical Drive
750GB SATA 7200rpm Hard Disk *** I now have a Samsung SSD 850 EVO 250GB which I intend to fit (hence this overhaul).
Creative X-Fi Extreme Audio
Compatiblity should be ok, but my knowledge is limited.
With regard to the ads - I looked mainly at Ebay (UK) under Computer Software - Windows 10, and there are pages of cheap offers. I am still not clear - are they really for the license plus the full program? After reading your comments I will give them a miss.