Windows 10 major lag in games

[tweaky123]

So I have dual boot, I got Windows 7 Ultimate and Windows 10 Professional.
Games when I play them in Windows 7 Ultimate don't lag at all, but when I run them in Windows 10, they lag as hell.
It's such a shame, I like the design on Windows 10, and the performance is poor, there are so many issues with it.
How can I solve that lag?

 

[RCFProd]

Maybe try a fully fresh Windows 10 install, with the storage completely formatted so the old OS, Windows 7, is gone.

Might be a confliction with your graphics card drivers. Running Windows 7 GPU drivers on Windows 10? You're going to get problems.

 

[tweaky123]

Maybe try a fully fresh Windows 10 install, with the storage completely formatted so the old OS, Windows 7, is gone.

Might be a confliction with your graphics card drivers. Running Windows 7 GPU drivers on Windows 10? You're going to get problems.

The lag was here before the dual boot, I have drivers made for Windows 10, not for Windows 7.

 

[RCFProd]

Maybe in Win 7 It's using your graphics card but using your onboard graphics in Win 10. The problem is not that detailed, not easy to help with I think.