Windows not booting (stuck at BIOS boot drive seleciton after Grub2Win installation)

[flx17]

Hello everyone,

I installed Grub2Win on Windows 10 64bit to dual boot with Linux, both OS are on different drives. After first boot attempt, everything looked good as the grub menu showed up. Then I accidentally chose the default top option (something windows boot manager ... ) and pressed esc to cancel. Now, my machine wont boot into Windows 10 (I get a black screen and then get back to BIOS to select the boot drive). From here, trying to boot windows brings me always back to BIOS boot drive selection. However, booting to Linux from here works just fine.

Not sure if this has anything to do with it, but since then my BIOS spontaneously freezes.

Please help me to get windows booting again and grub2win working as it should.

Thanks & best regards

[Drummer]

Hi Flx,

It sounds like either your MBR or Windows boot manager is corrupted. Or possibly a motherboard BIOS issue.

Note: Grub2Win does not touch either of these. Linux install sometimes alters the MBR.

What model machine is this? If the machine is very old, check the motherboard BIOS battery.

I suggest you try booting the Windows installation DVD and running the boot repair program.

Once you get Windows to boot, run Grub2Win and click the blue "Diagnostics" button. Then send me the C:\grub2\diagnose.7z file for analysis.

Please let me know how you make out.

Thanks,

Dave

[flx17]

Hi Drummer,

thank you for your quick response. My (fairly new) system runs on the B450M S2H chipset, this should not be an issue. I use GPT, not MBR. My drives are C (Win System), D (Win Data), E (Linux).

I have tried in the following order:
1) boot repair program, failed (no installation detected on any drive)
2) diskpart to repair boot stuff, failed (path to c:/boot not found)
3) system restore option (to a point where grub2win was not installed), windows still not booting
4) not having any better idea, I unplugged drive E and Windows boots directly (Windows does not boot when E is connected and disabled in BIOS boot options).
5) reinstalled grub2win and then ran the diagnostics (I do not know if the diagnostics are of any value to you this way), now windows again does not boot
6) multiple attempts with reinstalling grub2win, different drive configurations, some system restores and BIOS boot order changes. The only hint at grub2win working was a message that the config file is missing, I can not recreate this message.

For now Windows only boots when E is disconnected and the system is restored to a point where grub2win is not installed, like at point 4). As soon as I plug in E only once (or even disconnect it afterwards) I need to use system restore to get Windows booting again.

Maybe this is more of an issue due to GPT or with my motherboard/BIOS!?

If there is no other solution that comes to your mind, I might be better off not using grub2win for now.

Thanks,
flx17

[Drummer]

Hi again Felix,

I looked through your diagnostics. Everything looked good: firmware pointers, files, install logs etc.

It seems that there is something going on with your hardware, specifically drive E:

Grub2Win never touches Windows or boot files.
The fact that files are missing, again points to a hardware or firmware issue.

The problem is that critical files are not accessable whenever your E: drive is connected.

This sounds very much like a disk controller or drive that is locking up the I/O bus when physically connected.

Hope this helps,

Dave

[flx17]

Hey Dave,

once again thank you for your response! Of course this helps, at least now I can assume that grub2win is not the underlying problem. I will take a look at it as soon as I find the time for it.

Best regards,
flx17