Old configuration: Two MBR hdd, one with Win7 Ult x64, other with XP, separate boot partition. Win7 set in BCD as default boot. Asrock mobo with UEFI bios booting in legacy mode.
Next, added new large hdd formatted as GPT with UEFI and MSR partitions. Installed Win7 Pro + SP1 from DVD in UEFI mode, with other two hdd unplugged. Win 7 boots fine using UEFI boot to Windows Boot Mgr.
Reconnected other hdd and added 7 Pro as a third boot option to the BCD on the MBR boot drive, pointing to winload.exe on the GPT partition. No problem booting the GPT partition from the legacy boot.
In single hdd configuration, upgraded 7 Pro to Windows 10. 10 boots fine via WBM. Reconnected other hdd, and 10 still boots fine from WBM. Set boot drive back to legacy MBR. Deleted 7 Pro entry and added new entry for 10 Pro, again pointing to winload.exe on the GPT partition.
Although 7 Pro could boot fine from the GPT disk using the entry in the legacy BCD, Win 10 will not boot. I'm getting error 0xc0000428, "...cannot verify digital signature of winload.exe" Secure boot is disabled, so I don't know why I'm getting this. I can boot 10 fine using the BIOS boot menu to select WBM, or let it default to the legacy boot to start Win 7. So I can either add Win 7 to the boot menu used by WBM (how?), get 10 to boot from the legacy BCD (how?) or use the BIOS boot menu.
Please advise.
Next, added new large hdd formatted as GPT with UEFI and MSR partitions. Installed Win7 Pro + SP1 from DVD in UEFI mode, with other two hdd unplugged. Win 7 boots fine using UEFI boot to Windows Boot Mgr.
Reconnected other hdd and added 7 Pro as a third boot option to the BCD on the MBR boot drive, pointing to winload.exe on the GPT partition. No problem booting the GPT partition from the legacy boot.
In single hdd configuration, upgraded 7 Pro to Windows 10. 10 boots fine via WBM. Reconnected other hdd, and 10 still boots fine from WBM. Set boot drive back to legacy MBR. Deleted 7 Pro entry and added new entry for 10 Pro, again pointing to winload.exe on the GPT partition.
Although 7 Pro could boot fine from the GPT disk using the entry in the legacy BCD, Win 10 will not boot. I'm getting error 0xc0000428, "...cannot verify digital signature of winload.exe" Secure boot is disabled, so I don't know why I'm getting this. I can boot 10 fine using the BIOS boot menu to select WBM, or let it default to the legacy boot to start Win 7. So I can either add Win 7 to the boot menu used by WBM (how?), get 10 to boot from the legacy BCD (how?) or use the BIOS boot menu.
Please advise.