Is there a way to tweak Skyrim so that vertical cursor sensitivity = horizontal cursor sensitivity?
Skyrim Mouse Settings – How to Sync Vertical and Horizontal Sensitivity
mousepcthe-elder-scrolls-v-skyrim
Related Solutions
Usually this means that vertical sync is set, and you need to unset it, it's one of the most annoying things ever from computers that are slightly behind recommended specs.
The suggested SkyrimPrefs.ini i was using was the wrong one.
Using Process Monitor i was able to figure out that the correct one is:
%USERPROFILE%\Documents\My Games\Skyrim\SkyrimPrefs.ini
e.g.
C:\Users\Ian\Documents\My Games\Skyrim\SkyrimPrefs.ini
Changing [Controls]\fMouseHeadingSensitivity to
fMouseHeadingSensitivity=0.1250 (new)
fMouseHeadingSensitivity=0.0125 (old)
did the trick.
Best Answer
Under [controls] in Skyrim.ini (Found in "My Documents\My Games\Skyrim") there are two entries.
Change the YScale to match the XScale and all is well in the world again.