Windows 10 not showing in GRUB boot menu of Linux Mint

A rule of thumb for dual booting Linux and Windows is to install Windows first.

But as anomalies in the Matrix exist, doing so may cause to have only Linux in GRUB boot menu (the linux boot menu that let you choose the operating system you want to boot into).

There are GUI programs to fix this but i will show you the Terminal way. I know the linux Terminal is scary but you’ll se you have nothing to worry about.

Look at the bright side, it’s an exercise for linux Terminal and editing a text file.

So, it’s simple as that:

  1. Open a Terminal.
  2. Type without quotes: “sudo nano /etc/grub.d/40_custom”
  3. Enter your password.
  4. Add this to the file:

menuentry ‘Windows 10′ {

set root='(hd0,msdos1)’

chainloader +1

}

5. Save and exit the text editor.

6. Also on the Terminal, type without quotes: “sudo update-grub2”.

7. Enter your password.

8. Restart and enjoy.

 

How to install memtest86+ on a USB flash drive

It comes a time when your computer starts trowing on you some errors, restarts, blue screens of death and the only thing left is to start checking what is causing the problems.

One of the first things you should check is if you have a faulty RAM module.

The best tool for testing memory modules is memtest86+.

Where you can find Memtest:

  • On HirenBootCD.
  • On almost every linux distribution LiveCD.

If you remember the previous tutorial on this site about Puppy Linux on a bootable flash disk drive, the thing is, we don’t have memtest86+, but we can install it on the good old trusty linux on a stick to use memtest on any computer that can boot from USB.

We assume you have the Puppy Linux installed on a USB flash drive and we start from there:

  1. Boot your computer on Puppy from your USB drive.
  2. Go to Menu > System > Grub4Dos bootloader config.
  3. Select your USB drive and press OK.
  4. On the next screen just press OK to install GRUB bootloader (GRUB is menu system that lets you choose the OS/drive/app you want to boot into).
  5. Open a web Browser and go to the Memtest download website.
  6. Download the 3rd link (as of Memtest86+ V5.01 (27/09/2013), the one that points to memtest86+-5.01.bin.gz
  7. On the bottom of your Puppy Linux desktop open the root of your Puppy USB drive (mine is sdf1). Leave this window open.
  8. At the top of the Puppy Linux desktop open the file app (the one with a home icon on a folder).
  9. Press the Downloads folder. Here you will find the downloaded Memtest file.
  10. Right click and Rename. Rename it to memtest.bin.
  11. Now drag the file from step 10 to the window on step 7 to move the memtest.bin file there.
  12. Now, on the location you moved the memtest.bin file (your sdfx location=the root of your USB drive) you can see menu.lst (the menu for the GRUB bootloader).
  13. Open menu.lst and after the entry for Puppy linux, paste this (without the 14.):
  14. # memtest+
    title memtest86+ v5.0.1
    kernel /memtest.bin
    boot
  15. Close the file and reboot Puppy.

 

After rebooting the Puppy Linux USB drive, you will get the GRUB bootloader with some entries:

  • Puppy
  • Memtest
  • Windows (if you have it installed)

All entries shoot boot the appropriate OS/apps but to test our installation select Memtest and wait until it checks your RAM modules. Press ESC when done.

There you have it, you can test the memory on any USB bootable computer in the world.

Have fun and if you have questions, please shoot!

 

Grub rescue > and how to recover your boot menu and make changes permanently

A few days ago, after resizing some partitions on my hard-drive i did a restart and boom, no boot menu and i got this message:

unknown filesystem.

grub rescue>

What happened until now:

– i have 1 hard disk with dual boot setup with GRUB (linux boot menu) with Debian Linux and Windows.

– the Windows part has 2 partitions: C:\ with the system (bootable) and D:\with stuff.

– the Linux part have 3 partitions: root (/) (also bootable), home (/home) and swap.

– i shrinked with gParted the D: partition and grow the root and home partition on Linux.

– restart and ran into the grub rescue> problem above. What happened was that when resizing the root partition i screwed up the boot part.

The solution is basicaly to identify your linux bootable root partition and update the GRUB with the correct settings so that at the next boot, GRUB to be able to “read” all bootable partitions in your hard drive.

1. Make sure what is your Linux bootable root (/) partition. To do that, make sure you have the Debian Live DVD and boot into this DVD.

2. Go and try the Live image. Wait to load.

3. Open a Terminal.

4. At the prompt, type (the sudo -s won’t require a password):

sudo -s

fdisk -l

What i get was all the partitions and the bootable ones marked with *. I get something like:

Drive           Bootable      Type          Mount         Size        Etc……

/dev/sda1     *                 ntfs

/dev/sda2                        ntfs

/dev/sda3   ………… blah            blah

/dev/sda4                        ext4          /home

/dev/sda5                        swap

/dev/sda6    *                  ext4          /

5. So the Linux root bootable partition will be /dev/sda6. TRY TO UNDERSTAND THIS: so it’s on the first drive (sda) and on the 6th partition (sda6). At point 7. you will understand.

6. Restart and take the Debian/Ubuntu Live DVD out.

7. Back at the grub rescue> you should type each line followed by [Enter]:

grub rescue>set boot=(hd0,msdos6)

grub rescue>set prefix=(hd0,msdos6)/boot/grub

grub rescue>insmod normal

grub rescue>normal

8. You are back at the lost boot menu. ^-^. Boot into Linux.

Back on track, but if you restart the computer, you will be back to the grub rescue> problem. So to make the changes to GRUB that will be permanent, we should reinstall GRUB on the hard drive and update the GRUB menu:

9. Open a Terminal and type (Now for every sudo command you should enter your user password):

sudo grub-install /dev/sda

sudo update-grub

10. That’s it! Your changes to the boot menu ar permanent.

NOTE: If Windows won’t boot, use a Windows installer DVD and do a Stratup Repair.

Have fun! ^-^