With Win10 you've had 29 shares in 4 hours, and with Win7 you've had 24 shares in 6 hours. Noticeable, but still within the normal variance range (4-6 hours is not a long enough period to make any definitive conclusions). There's 2 weeks between the screenshots, so maybe Nanopool has changed their difficulty? Right now it seems to be 5 billion. Do you remember what it was 2 weeks ago?