Hello guys,

I have been using Windows 10 for sometime, and decided to dual boot with Linux Mint. I have been following this video for guidance:
https://www.youtube.com/watch?v=V1XqHFgpqxc

I was using a Toshiba Satellite so I switched the boot mode to CSM.

I was doing ok until when I needed to make partitions to install Linux along with Windows. The video time is at 4:20. But instead of only two /dev/sda partitions, I was greeted with 5 /dev/sda partitions. In addition to this, there was only 2 1 MB freespace partitions and only 1 0 MB freepsace partition.

Out of desperation, I started deleting the /dev/sda partitions to allocate free space for swap memory. But in doing so, I deleted the /dev/sda/1 partiton in the process. I believe this was the folder for Windows recovery.

Regardless, I was able to install Linux Mint but wasn't greeted with Windows 10 as an option in the grub loader. I tried switching my boot mode to UEFI, but that results with an error message and no bootable disk.

Does anyone know a solution to this? Thanks in advance

The youtube video you linked to looks like an MBR install as there is no EFI partition. Was your windows 10 pre-installed? If so, it was probably UEFI and you would have needed to boot and install Mint UEFI or you would have trouble booting.

Boot Mint and open a terminal and run this command and post the output here: sudo fdisk -l(Lower Case Letter L in the command)

sda1 is too small to be a Recovery partition so it was probably the boot partition. If it was a FAT32 partition I would expect it to be an EFI partition but it is an ntfs partition.

You might be better off posting more details on your system which you can do by getting the 'boot repair' software from the link below. Download it to Mint as instructed and run it from Mint or download it and burn it to a CD. Whichever option you select, make sure you select the option to Create BootInfo Summary and post a link to the output here. Do not try to make any repairs.

https://help.ubuntu.com/community/Boot-Repair

Hi, and welcome to LQ,

Ah, you made a mess there.

Since you saw 5 partitions, it means your laptop hard disk is formatted with the GUID partition table - GPT (as opposed to MBR) and that the laptop uses UEFI as default.

You see, machines have changed in the recent years. In order to accomodate more partitions on hard drives whose size are increasing over 2TB, the GPT system was invented. Now you are not limited to 4 primary partitions on a hard disk and you can do many many more.

But this new system comes at a cost as they also invented a new way to boot, the UEFI.
https://www.howtogeek.com/56958/htg-...lace-the-bios/
https://www.howtogeek.com/56958/htg-...lace-the-bios/

This new system does not use the MBR boot sector but a whole partition called the EFI partition (usually sda1 or sda2) to hold boot loaders. It usually is a FAT32 filesystem some 500MB in size. It holds the Windows boot loaders in EFI/Microsoft/Boot and your Mint bootloader come in EFI/ubuntu/ I think.

The problem is we do not know which partition you deleted as I have seen on some laptops, that sda1 is not the EFI partition but it is a Windows System Reserved partition. I don't know what Windows use it for but if you deleted that, I think Windows will not be running correctly. When you switched settings to CSM, you actually disabled UEFI and switched to Legacy BIOS. Mint probably didn't need the EFI partition then, so didn't report any error, but I think Windows will not boot in Legacy mode.

Did you make recovery disks for the Windows before you install Mint?
Do you have an option in the BIOS to restore/recover such that it is back to the factory state?

If you can restore the laptop to its original state, we can then guide you to install Mint in UEFI mode. It is not difficult. Then you'll be able to dual boot easily. If you can't do that, try to see if you have Windows repair disk. You could tell Windows to repair its own bootloader, which it will probably do at the expense of Mint. Then, you'll just need to repair the Mint or reinstall it.

I'm saying this because the present state of the system seems pretty difficult to mend, although not impossible.

1 members found this post helpful.

I didn't think of making recovery disks for Windows. And I checked the BIOS and it doesn't have any options for resetting. How would I exactly obtain the Windows repair disk. Will I need a product key or digital licence to do this?

Well, maybe Microsoft lets you download a repair disk freely.

Do you have a product key?

I had Windows 8 original on a laptop along with its product key and I downloaded Windows 10 DVD freely and upgraded the Windows 8.

Before you do anything, you can access the Windows partition from inside Mint and backup all your data.

Ok... it was long time since I responded but I finally recovered Windows, but at the cost of Mint. There was a Windows 10 disk online which helped me reinstall Win10. But it had to do a clean install on the CSM boot mode. I backed my files, so recovering them wasn't a hassle. Now I'm wondering how to dual boot and if I should change to another distro instead of Mint by your preference. (E.g. Ubuntu, Debian, etc.)

Mint is based on Ubuntu, Ubuntu is based on Debian. Just a personal preference. No reason to switch from Mint unless you want to. If you are not using UEFI for your windows, just boot windows and shrink the windows partition to leave unallocated space on the drive on which to install. The link below is a tutorial which also explains how to check if you have CSM or EFI.

https://itsfoss.com/guide-install-li...-boot-windows/