[How-To][Windows, Linux, cloudready][UEFI][GRUB] Successful Triple Boot (working on Lenovo T420)

First of all:

I’m not responsible for any damage done to your device. You have been warned.

That being said, it is best if you make a complete backup of your device. I can’t advise you on how to do that, because that wuld include specs about all different systems. If you’re an IT guy like me, I’d just say, maybe you should just switch to a different hard drive, preferrably a new SSD, and keep all of your old data on the existing one. That way, you can revert by restore BIOS settings (if needed) and just switch the disks back.


  1. Backup your Operating system(s) disk(s) or at least all userdata from your system disk – depending, what you need. THIS IS IMPORTANT
  2. Make sure you’re on UEFI
  3. Considerations for partitioning
  4. Install Windows
  5. Install cloudready
  6. Install Linux
  7. Restore your data
  8. (optional) Modify Bootmenu

0. [Update:] Don’t do it – unless you REALLY have to.

Please stay away from cloudready. The support and the disadvantages outweigh the simplicity by far. I have considered it for my mom, who is – let’s put it this way – not tech-savy. Now she has a ubuntu / windows dual boot (windows just for *emergency*) and I no longer get support calls. No java, flash, adobe or antivirus popups, no browser messages (thanks ublock / ghostery) or annoying notifications.

You won’t be able to update and patch the thing. If you’re that advanced and think about doing it, you might agree.

1. Do your backups.

(maybe I will add some resources on how to find tools and how to speed up that process)


I don’t need to tell you what UEFI is (the successor of BIOS – specifically it’s UEFI-BIOS), just make sure you already use it. If not, be warned: you can not just flip a switch, you need to reinstall ALL EXISTING OS. You could change your OS’s, but even I, as IT Pro, was not willing to go through that process, since I needed to backup my data anyway beforehand and the restore process afterwards was considered less complicated.

Go to your BIOS and check your boot options. There will mostly be at least two options BIOS (legacy), UEFI and/or Both. I’ve had Legacy only since otherwise back in the days I could not PXE boot, but nevermind.

I’d advise to flip to UEFI (only) and not “both” sine you have no real way to determine before the first installation, which mode your first OS will be installed in ;)

If you flipped the switch, you might realize, that your OS will no longer boot. Don’t panic just yet if you missed something, you can flip it back and it will work again, as long as you did not install something over.

You also should have your installation media (ISO is good – on a different drive, of course), your windows key would be great as well.

3. Partitioning

I have specific needs, and so do you. So take a look at your current disk usage and make your own considerations when talking about partition sizes.

My needs were:

approx. 50GB for Windows
approx. 32GB for cloudready (like recommended, I’d even used less, but whatever)
10-15GB for Linux (I use Xubuntu, so it depends on your setup)
Though I have a 256GB SSD, the Linux partition now (day 3 after first install) takes about ten times the space it really needs, so I will shrink it afterwards
Why Windows so small? I am not a gamer, nor do I have stored any personal data on my system drive. Almost everything user-related is stored on my second drive or will get backupped or just outsourced to my NAS / Cloud services.

Also I use very few applications, in fact, I mostly use Linux in my day-to-day use. Windows is for backwards compatability and could be obtained for 15 bucks so I took it as a good option.

Look, how many GB your Windows is using now, If you have 1 200GB drive and windows Uses 150GB of your partition I highly advise to not even consider to shrink it. 75% usage will result just in too little free space.

General recommendations:

Plan all partitions for some GB growth.
Plan for at least 20% free space AFTER growth.

Fragmentation will even occur on Linux if you plan wrong.
Windows Fragmentation will become even worse.
Example: If your Windows uses 80GB you could plan for maybe 120-130GB of windows, 32GB of cloudready, so you’d need at least 10GB for Linux – for a total of 172GB + X

tl;dr: a 200GB drive or more is recommended for triple boot.

My approach for you would be in general something like this:

20-30GB for Linux
32 GB for cloudready
Windows: the rest.
If you don’t agree: GOOD. That means, that you already know your needs and could have skipped this section.

Write down your setup, don’t do it on the fly if you’re not experienced..

4. Install Windows

Create a bootable media and (re)install Windows.

Depending on your disk, if you used a new disk or need to repartition your current one (did you already backup?) you might follow different steps.

For creating the bootabIe media I recommend rufus. (https://rufus.akeo.ie/) I wanted to create a multiboot media at some point, because I did so previosly for my BIOS hosts, but UEFI is not supported that wide, so I jost sticked to either multiple diffent USB drives or just use the same drive and re-deploy my install media anew each time.

You might need to enter the advanced options in order to remove all existing partitions for which it really would help to have all disks other than the system disk removed, so that you don’t accidentally remove a partition from your second disk (the tools by microsoft are horrible from the point of user experience…)

And choose to install – without creating partitions manually. Just let windows take care – you don’t need more partitions or more space at this point.

[do your windows thingy]

5. Install cloudready

At this point you need to:

  • shrink your windows partition
  • create your install media
  • install cloudready

Open your disk management (right-click “my pc” – manage) ->  disk management
right-click your windows partition – choose shrink. shrink it to the size, you specified earlier don’t count too exact, to make it more fun ; )
The important line is “total size after shrink”. And again, MS counts in Megabytes. In 2017. *sigh*

Shrink only so much, that your free space must not exceed the size, you want to give to cloudready! The installer will take all the available space!

Create cloudready install media according to their tutorial.

Boot the stick and install the thing!

[do your cloudready thingz]

You should see a bootloader at boot, where you can switch now between cloudready and Windows. But we wanted more, didn’t we? ; )

Install Linux

first you should boot back to Windows.

  • shrink your windows partition to gain new free space for you linux distribution
  • create your linux install media

Now you have two options, either shrink your windows to your target size of “the rest”, which means you might be a regular user. OR you shrink your windows partition to “what I really need” which means, that after your linux installation you might have space for your user data. In either case, do your partitioning like mentioned earlier.

Likewise your install media.

You can boot now from your USB, to install the thing.

I did give windows like 50GB and let Linux use the whole rest of my free space for now.

[do your Linux things]

Restore your data

[coming soon, if needed.]

Modify GRUB

After the installations, your GRUB menu might look really messy. You can clean it up though. I will provide my steps later on.


I will provide actual settings for the boot image creator if needed.

[coming soon.]

Issues I ran into (tbc):

  • Second disk was accidentally tried by neverware installer
  • Screwed up partition layout, had to retry
  • Messed up GRUB menu, needed to clean up afterwards

[coming soon, if needed.]



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