Source
r/linuxquestions•
GregJ7

Messed up Win 10 installation with Linux installer

I had a Windows 10 installation working (for months), and wanted to make another partition to boot a Linux distro from. The Linux installer requires manual partitioning. I've tried most of the following both with the partition as unallocated and formatted as Ext2 or Ext4.

While in Manujuro-KDE Linux Installer (Calamares), I discovered that it wouldn't accept that new partition to progress to the next step, including after making the Ext4 partition an extended partition with Ext4 + /boot/efi + esf + settings. I did not figure out a way to proceed.

I rebooted to Windows 10, well, tried to boot to Windows 10, but my UEFI couldn't find an operating system. Booting from a Windows 10 Installation Media (USB), none of the troubleshooting features worked, including "upgrading" the install with new files, but when I try to Install Windows 10 fresh (not deleting the files) I am told that:

Windows cannot be installed on this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks.

Presumably the installer did something "special" that I did not intend. I would call it a day and wipe the hard disk, except that I can boot to a command prompt and directory listing shows all the files there just fine.

What does the Windows 10 installer erroneously think about that SSD partition now? How can I fix it?

Posted Jul 2, 2019, 7:26 PM UTC · edited

37
PedanticDilettante•

Am I understanding correctly all this happened on a single disk? You used the Linux installer and tried to modify the partition scheme on a disk that already had been formated GPT with at least one parition dedicated to Windows? If you attempted to modify the partitioning scheme you have likely wiped the partition table.

You cannot simply resize a Windows partition within the Linux installer without data loss and making the existing installation irretrievable. Also, if you are formatting an existing GPT disk as MBR that too would immediately wipe the existing partitioning scheme of the disk as that is a disk wide operation. At this point the only option is data recovery with a forensic file carver and a fresh operating system install.

2
GregJ7OP•

From Windows I had a 660 GB partition and 250 GB unallocated on a 1 TB SSD. From Linux I only was trying to change the 250 GB to something I could install Linux on. I also tried this with the 250 GB allocated as a partition formatted to Ext2 (formatted from Windows). (Calamares didn't know how to.)

1
ImKindaHighBut•

If you really want to know if you deleted your data, you could just as easily boot back into the Manjaro disk and attempt to read it.

1
sidusnare•

That's what we call a win-win.

1
Ucla_The_Mok•

Sounds like you messed up the Windows partition.

You're probably going to need to delete all partitions in order to reinstall Windows.

Edit-

In case you're wondering why I said that even though you can see the files from a command prompt-

You can change a disk from MBR to GPT partition style as long as the disk contains no partitions or volumes.

https://docs.microsoft.com/en-us/windows-server/storage/disk-management/change-an-mbr-disk-into-a-gpt-disk

1
GregJ7OP•

Thanks for this info.

1
GregJ7OP•

Final Result is that I wiped the SSD and created multiple partitions. After that my UEFI recognized that it could boot to a boot menu—it hadn't been an option before, presumably because the SSD was originally just one big partition. I installed Windows 10 on one partition, then Manjaro on another. Then I discovered that some disk utility I used from Manjaro didn't play nice and it scrozzled my Windows 10 installation (again, except the first time I figured it was my fault). I reinstalled Windows 10 using the whole SSD. At that point I was willing to buy another SSD for Linux Systems, unfortunately I was having trouble with ethernet connectivity and discovered that there are no Linux drivers for my ASUS RoG Maximus VI Hero motherboard. Not sure I should have known better than to assume there would be drivers for Linux, but I've shot about 4 days and gotten nothing tangible from it, although I am glad to have a clean install without all the normal accumulated Windows crap. It is disheartening to find my system which is fast enough (i7-4770K) needs to be replaced to just use Linux. Fortunately what I learned about Linux was worth it—many useful things, but also that Firefox likes to lock up or crash. Having complete backups of my data on an old secondary HD (as well as online) just paid for itself in saved time restoring my 100+ GB of personal data. Twice.

I learned not to trust the Manjaro installer or Linux disk utilities (until I learn more) to only access its partition. I learned not to trust Windows 10 disk utilities, either, since on an entirely repartitioned and quick-formatted SSD, I came across a dialog box a single time showing old files that should have been impossible to see. Windows disk utilities (being tiny, featureless things) have worked 100% for me for decades—until now.

By the way, wait to get that 4K monitor. It seems that most distros, including their ancestors, don't have the kind of support you want if you buy a 4K monitor.

It also occurs to me again that there is no way in reddit to write a response in this thread to everyone (such that they will be notified of a new post, something that should be permitted by the original poster, at least).

1