Hi and sorry for my English... I have a PC with a solid NVME disk in PCI-e mode connected to its M2 port. I have installed Windows 10 Pro and I have configured the bios so that the 1st boot option is the windows boot manager that is on that NVME disk. Every time the PC started it was very fast to enter Windows and the disk manager appeared as disk 0. Up to here everything worked perfectly !!! The problem starts when I connect the second HD Sata3 disk that I want it for data. Now when I start the PC it takes a lot to start Windows 10 (which is in the NVME) and when I go to the disk manager to initialize the HD Sata and format the solid disk NVME that was disk 0 when I was alone, now it appears now as a disk 1 and the new HD Sata that I am going to format appears as disk 0. When connecting this HD Sata in the PC the numbering of the discs has been changed when the logical thing is that if the NVME was disk 0 it would follow in 0 and when adding the Hd Sata it would appear as disk 1. And the other problem is that now the boot is much slower. In my opinion it is as if I were looking for the boot on disk 0 which is now the Sata and when it is not found out to disk 1 which is now the NVME although in Bios I have as the 1st boot option the NVME where the Windows is boot manager The boot should be on disk 0 but the problem is that when I only connect the solid disk NVME in PCI-e mode it recognizes it as disk 0 but when I connect the 2 disks (NVME mode PCI-E and HD Sata3) it changes the order of the discs and the disc 0 that was the Nvme happens to disk 1 and the HD Sata3 that I have not yet formatted goes to disc 0 and it generates slowness to me when starting. I hope you can help me correct this. All I want is for the Solid NVME disk to remain disk 0 and boot the PC from it and for the Sata3 disk to be configured as disk 1. The board is an Asus Maximus XI Hero (wifi). Sata's PCH Storage Configuration is in AHCI Solid NVME disk is in PCI-E mode on M2 port _1 I hope you can help me because I've tried everything.