No grub after installation of Prime os

snaps

Decided to install prime os on an old Lenovo b595 as dual boot. Installation went fine alongside windows 10. I selected adding grub 2. But when laptop boots it goes straight into windows, no sign of grub to select os.

I created a new partition before installation, which then during prime installation formatted to EX4.

Johnboy1951

Did you install Grub to the MBR or the partition?

snaps

Johnboy1951 wrote: »

Did you install Grub to the MBR or the partition?

Not 100% sure. Any way of finding out?

It asked about making an entry in grub after formatting the partition, then added an entry into grub for the windows installation.

Johnboy1951

I would use a boot manager live session to boot the install and then reinstall Grub when running ..... making sure it installed correctly.

There are several such live utilities rEFInd is the one I prefer.

http://www.rodsbooks.com/refind/getting.html

I am sure there are many others ..... might even be something Win based but I would not know about that.

snaps

Not sure if it is related but I had to repair the MBR last year due to boot up problems.

I can remember I had dual boot windows 10 and elementary running with grub before. I took elementary off to free up disk space over a year ago. But since then I got a new machine, so disk space wasn't important.

Johnboy1951

You could try installing it again to see if you get a different result ........ keep a watch for where it installs Grub ..... it might put it on a different drive if one is attached.

snaps

Johnboy1951 wrote: »

You could try installing it again to see if you get a different result ........ keep a watch for where it installs Grub ..... it might put it on a different drive if one is attached.

Strangely re installing prime doesn't do anything in regards to grub.
I'll try a grub fixer today, I've tried boot repair disk in automatic mode, that says it fixes grub but it doesn't.
Maybe easybcd would work?

It's like the windows loader takes priority.

Johnboy1951

Maybe ........ are you shutting down Windows completely or is it hibernating (fast boot or whatever they call it)?

Shut Win down properly and then try booting.

snaps

Just getting back to you, I gave up in the end. I even reinstalled everything as a last resort to get it working. Tried legacy and uefi modes on installation.
I created a 513mb fat32 partition and a ext 4 partition for prime os and grub worked fine.
As soon as windows came into the equation grub dissapeared, didn't matter if I installed Windows first or second.
So anyway, in the end I used easybcd and this has worked, not as I want but long winded I've got dual boot.
So far I've found PrimeOs fantastic.

Johnboy1951

snaps wrote: »

Just getting back to you, I gave up in the end. I even reinstalled everything as a last resort to get it working. Tried legacy and uefi modes on installation.
I created a 513mb fat32 partition and a ext 4 partition for prime os and grub worked fine.
As soon as windows came into the equation grub dissapeared, didn't matter if I installed Windows first or second.
So anyway, in the end I used easybcd and this has worked, not as I want but long winded I've got dual boot.
So far I've found PrimeOs fantastic.

Glad you found a solution that works for you

If you were using EFI booting then you would have need to set the order of the booting OSs in the EFI.
This can be done from within Linux using
efibootmgr
and presumable from within Win also.

If using MBR then Grub should have overwritten the Win boot flag in the MBR and given control to Grub, from which either OS could be booted.

Given what you have experienced, it seems that the Grub install was not overwriting the Win boot flag and the only way I know to reliably change that would be to write zeros to the location and reinstall Grub.

All of no importance now that you have everything working

snaps

What was strange was grub was actually over writing the win bootloader, but the entries in grub wouldn't boot both operating systems. Selecting an Os just made computer reboot back to grub.

It's strange that only on this laptop have I had these problems. All other dual boot installs I have done Linux after windows, the grub works fine.

I read that HP owners also have a similar problem.

Johnboy1951

snaps wrote: »

What was strange was grub was actually over writing the win bootloader, but the entries in grub wouldn't boot both operating systems. Selecting an Os just made computer reboot back to grub.

It's strange that only on this laptop have I had these problems. All other dual boot installs I have done Linux after windows, the grub works fine.

I read that HP owners also have a similar problem.

The grub.cfg boot entries compared to the partition details might have thrown up some problem, as that reads like either the drive or the partition numbers were incorrect.
Sometimes partition numbers might not be in correct order and this just *might* cause a problem, depending on how the grub installer functions.