The main reason I am creating this guide is to help anyone who may be encountering issues getting through the 'dark' sections when being hunted by Fenrir in the Windows 10 version of the game.
During my play through I was unable to reach from one point of light to the next without getting caught and ultimately killed by the beast. The visual effects caused enough of a frame rate drop for my PC that it slowed me down in game enough to fail the section. By lowering the graphics settings to minimum the section can be completed without issue. In my case I had the following:Resolution: 1024x768
Display Mode: Windowed
Quality: Low (all else low)
If you are looking for help solving puzzles in chapter 10, leading up to the fight with Fenrir, you can follow this YouTube video or consult one of the more helpful guides for the Xbox version of Hellblade. All credit goes to the respective creators.