I notice that Paint.NET was slow on Windows 10 compare to Windows 7 on the same machine(i7 6700 & 16GB & ssd). Btw I had dual boot so I did a direct comparison and I notice that in Windows 7 the cpu usage was 100% on the other hand on Windows 10 the cpu usage was like 50-65% on the same exact task, as a result the same task X on w10 it takes 80 seconds complete and on w7 only 50 seconds .(btw I work with high rez images 18000x900 with multiple layers that is why speed is important to me)