Clover wont boot anymore, even from USB

[MisterNo]

Today I installed Sierra on 1Tb HDD, transfered data from El Capitan on SSD, then erased el capitan and put Sierra on SSD.

So, I had two Sierra drives working, and I also had Win 10 on another HDD, also working.

But, then something went ape **** with windows 10 installation, and I lost the ability to boot Siera.

But thats not all, I even cant boot Sierra Install USB, whatever drive I select to boot, whatever options I select in BIOS, my computer is trying to boot snd repair windows, wich he fails to do.
I tried turning of hard drives, but nothing helps! If i plug out windows drive and I try to boot sierra from hdd, ssd or usb, I just have a blank cursor on monitor!

I checked all the drives with gparted, all sierra drives are healthy and their efi partitions are active, only windows 10 drive is having issues.

Clear CMOS does not help.

WTF is going on? What do I need to do to boot at least my USB Sierra install?

It seems to be some kind of boot issue, is there any way to clear all boot informations from my computer, so I can try to run my USB installer?

 

[Going Bald]

Reset UEFI to optimum defaults, then make the changes you made the first time you installed OS X. i.e SATA mode = AHCI, disable VT-d, etc.

 

[pmdevita]

If your USB was plugged in when installing Windows 10, it may have put a copy of it's EFI on the drive. If you can still access El Capitan, rebuild the thumb drive.