This works on the Microsoft Surface Pro 1 or the Surface Pro 2. It’s helped me a LOT on my Surface Pro 2, may pen is far more accurate than it was. The 16 point calibration is just not enough. This is a 100 point calibration, and it’s well worth doing. Swipe in from the right, go to search, type CMD Open CMD (Command Prompt) and a black Windows will appear on your desktop with a flashing cursor Into the Command Prompt copy and paste the following:
tabcal lincal novalidate XGridPts=10,60,110,360,660,960,1260,1560,1860,1910 YGridPts=10,60,170,330,490,650,810,970,1020,1070
It will appear as one line, one command. Run that command by pressing enter and allowing the rights from the pop-up. This enters you into the calibration settings. Once your done your pen will be so much more accurate!