Whilst being perfectly happy with Win 7 Pro, I have also tried Win 10 pro and noticed a "peculiarity" using Pianoteq 5.8.1
Using a similar laptop with identical cpu, ram etc, I notice that the bench mark was "40", whilst using Win 7 there was a significant improvement of the bench mark (x+10).
I assume that I need to tweek Win 10, otherwise what would be the point in a software upgrade to 10.
I can't compare, since I started with a Windows 10 Surface Pro 4, but the upgrade to the Grotrian sacked my system!
My performance level runs between 40 and 50. If I am just playing the piano, with instruments older than the Grotrian, I have no issues. If I am playing Grotrian, and the computer is doing absolutely anything else, such as if I am making adjustments with the mouse on the screen, running a video or playing music from an Internet page, etc., the audio level graph jumps from a nice reasonable yellow bar that is 10 – 30% of the way up the scale to creating full-height red spikes heard as audible pops and clicks. It seems to make no difference whether I turn CPU autoload detection on or off. If I do not want such behavior (such as if I am trying to play and accompaniment to something on YouTube video, or if I am just sitting and reading email while idly giving my brain and fingers something else to do in the background, I have to reduce the Pianoteq internal sampling rate to 22050 or less.
i suspect Windows 10 does a _lot_ more "background processing" than Windows 7.
If you search the Forum, you'll find a few threads on "optimizing Windows". They may be helpful.
. Charles