I am going to expand on Julian's answer and add some more troubleshooting problems I had. I was setting up a Windows 10-Ubuntu 18.04 dual-boot on a refurbished laptop.
- First update laptop bios if needed. Just google "$my_laptop_model bios update" and you should find an official utility to update.
- Check if Windows is booted in Legacy BIOS or UEFI mode. Hit
Win+R and run
msinfo32.exe. Under "System Summary" there will be a "BIOS mode" which should be
- If BIOS mode is
Legacy then you need to convert to UEFI with MBR2GPT.EXE (its on all Windows 10 version 1703 or later PC's). I re-merged my Ubuntu partition into the Windows parition, then ran
mbr2gpt /convert /allowfullOS.
- Once this is complete open your bios (should do this by hitting f12 during boot sequence). Go to the BOOT tab and ensure that BIOS is booting into UEFI only, not "legacy", "both", or "uefi first".
- Download ubuntu ISO and mount to a FAT32 formatted USB drive using unetbootin
- Reboot and change boot order (f2 or f8 during startup) to load the USB first. Boot into the usb, select "Install Ubuntu", shrink the main Windows Partition and format to ext4 with a
/ mount point. Maybe add a swap partition. Install Ubuntu on the new parition.
Install should succeed. If Ubuntu does not appear in the boot menu during next startup, boot into the USB and select "Try Ubuntu". Open a terminal and install and run boot-repair
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair
Ubuntu should work!
I had a ton of errors install 18, that did not appear if I formatted my usb with Ubuntu 16. Stuff like
SQUASHFS error: squashfs_read_data failed to read block 0x2f12cf1e
[1889.190202] blk_update_request: I/O error, devloop0, sector 1542506
[1889.190271] SQUASHFS error: Unable to read fragment cache entry [2f12cf1e]
[1889.190271] SQUASHFS error: Unable to read page, block 2f12cf1e, size 697d
I read an answer somewhere that switching out the USB with another can solve this problem, but I didn't have any others. I just kept reformatting and mounting the Ubuntu 18 installation media on the same USB. Each time installation would fail at a different place. Eventually (over a day) it succeeded in entirety and the installation has been working well. GLHF