Sound issue on macbook pro 2011 running Windows 10

[yerlikzhan]

Hey, maybe someone can help me? I searched a lot and did not find solution. I found out that the sound problem is because of EFI boot. Tried couple of suggested solutions, like to install windows from CD instead of USB, so installation will be in legacy mode, but unfortunatelly I replaced DVD drive with optibay so don't have DVD drive. I used usb DVD drive and when I restart mac OS from Bootcamp and it tries to load in legacy mode I only see black screen with blinking cursor and installation doesn't start. I waited couple hours and then gave up. Then I found that I can install Windows from USB and just change EFI boot to Legacy boot using Winclone, making Bootcamp drive legacy bootable. To do it I installed 2nd OS X (El Capitan) on my mac, because didn't find free winclone for Sierra OS. Changed boot mode for Bootcamp drive, and after restarting with bootcamp from OS X shows black screen with statement "No bootable device found, please insert bootable device and press any key". Then I thought I can load Windows holdin option key at startup, no, I don't see anymore EFI or Windows in boot options. So I changed back EFI boot on bootcamp drive to load Windows 10. One thing to mention, during installation from USB I changed MBR: status of the drive with OS X and Windows from hybrid to protected using GPT fdisk, since Windows 10 rejects MBR drives. I bet the legayc boot problem hides here. Any suggestions would be appretiated. help please!