Switching Off "Secure Boot" in BIOS / UEFI stops OS loading

Whilst trying to get my duel boot W10/W7 on separate drives to work (some of the issues of my own making) I read about switching of "Secure Boot".
I have a ASUS P8Z77-V LX motherboard and when disabling Secure Boot, I am requested to identify the OS in use, non being Microsoft, and regardless of which I pick, the system would not boot into either W10 or W7 with "OS not found"
However as suggested in other threads to get my W7 back up and running I just unplugged my W10 drive, and I use the BIOS "F8" to swap drives with my W10 drive as default.

Hi,
I believe one needs to delete the existing secure boot keys as well sometime just to be able to switch secure boot off.
Fast start too would need to be disabled.
You might also need to make sure other os is selected instead of boot uefi only.
Why does the “Secure Boot Violation� appear when I enter my WINDOWS 7 OS? | Official Support | ASUS Global

@ThrashZone Many thanks, on checking my BIOS Boot/Secure Boot the screen looks like this:



If I switch to Other OS, there are no choices, if I then go into Key Management I get this screen:



As you will see PK is already unloaded.

The page you directed me at I found quite confusing, and it would seem that my BIOS/UEFI is set-up in a manner that does not require secure boot to be disabled; however many thanks for the direction.

Hi,

Secure boot should be set to off for W7. How did you install this?
Best way is when installing on separate drives is by disconnecting the one you're not going to use for installation.
Otherwise there's a good chance the boot record is going to land on the drive that already had one.

Cheers,

fdegrove said:

Hi,

Secure boot should be set to off for W7. How did you install this?
Best way is when installing on separate drives is by disconnecting the one you're not going to use for installation.
Otherwise there's a good chance the boot record is going to land on the drive that already had one.

Cheers,

Secure boot has been on ever since I bought the motherboard some five years ago, and until I used this forum I didn't understand what it was supposed to do.

I have W7 running on one drive, and went to install W10 on a new drive, but in my enthusiasm, corrupted my system. I them (clean) reinstalled W10, and again all was good, but I then "broke" my W7 (teach me to "play") partly playing in the BIOS and secure boot. I removed the SATA connection for my W10 drive, clean installed W7, then plugged my W10 back in. This is a couple of weeks ago and all seems OK, but I don't wish to speak too soon; if you know what I mean.

Hi,

Good to see you have it working again then. Maybe a full image backup of both installs is in order ? Macrium Reflect Free springs to mind...

Best,

Hi,
I would imagine you'd need to install 10 as Other os otherwise it would clash with 7 installed in uefi compatibility mode.
As the link showed switching 7's install to other os just solves the boot violation error if the windows update was installed.

fdegrove said:

Hi,

Good to see you have it working again then. Maybe a full image backup of both installs is in order ? Macrium Reflect Free springs to mind...

Best,

Hi,
System images do not help bios changes
But never hurt the os's state :)

fdegrove said:

Hi,

Good to see you have it working again then. Maybe a full image backup of both installs is in order ? Macrium Reflect Free springs to mind...

Best,

It has been done; foolish not to, mind, it was my foolish actions in the first place that lead to to issues, but provides some good learning, but it was the hard way.

Hi,
If you can live without it fast start in win-10 should also be disable too for good measure using command prompt as admin with

Code:

powercfg -h off