To cut a huge long story short, I tried to do the pro upgrade using the 10 dummy key and then my TechNet keys and found that 10 will not accept my TechNet keys, but 8.1 will. After a lot of pain I have my Linx 8 back on 10 Pro and activated.
However, somewhere along the way, the touch calibration has gone completely gaga. I've tried every thing I can see and think of including downloading the drivers from this site, completely uninstalling and reinstalling the drivers, with driver deletion and tabcal forced to landscape with 36 points.
The result is always the same, calibration completed successfully every time but when I touch the tablet afterwards the touch is always registered half way across the tablet (or more). You can see that with the visible touch telltale.
Any ideas? Initially I thought it was due to the upside down orientation I was not able to fix, but after finding the values to change the reg key for 8.1, I finally managed to do the pro 10 upgrade and the values were correct. The 8.1 values flipped it again. So I don't believe it has to do with the orientation. Unless the touch thinks it's in a different orientation than the actual screen??