Installing Ubuntu alongside with Windows

Question

I'm trying to install Ubuntu without deleting windows from my computer, how can I partition free space without deleting anything

Answer 1

You need not worry about "pre-partitioning". Ubuntu installer has a partitioning manager that will make everything clear.

Its default is not to "delete windows". In fact, you'd have to go way out of your way to accomplish this.

There are pre-preemptive steps you must take Windows-side though to ensure Ubuntu may actually boot.

Contrary to any other OS, Windows will attempt to keep the drive in a read state on hibernate (and shutdown/restart which in latest Windows 10 also defer to fake-hibernate).

So if you follow Windows's own procedure for adding a dual boot, Windows should do the necessary to disable its own rigging of the hard drives on that particular reboot which will ensure that Ubuntu won't write itself to the disk, then fail to obtain the rights to write its own loader which will result in no dual-boot after the installation, just Windows, and you feeling like the Ubuntu installer didn't do anything.

So, assuming you're under Windows 10:

1. make sure your Ubuntu live USB key is inserted.
2. open up a CMD
3. type powercfg -h off

Go to Settings -> Update and Security:

Recovery -> (Advanced startup) Restart now:

This will reboot to this:

You'll then be able to select your Ubuntu key and if you follow its instructions, everything should go according to plan.

This is one of the easy screens you'll be faced with (this one allows you to do the partitioning work, with a simple slider that stops sliding at used space in your Windows partition, so no risks to be had (similarly; the minimum partition size for ubuntu will prevent the slider from reducing the ubuntu partition under 10GB):

If, on the other hand, you get this screen :

then, follow this video tutorial :

https://www.youtube.com/watch?v=OU_dkeFprhY

in the above screenshot, select the line that has "/windows" and click the "change" button, this will open up a modal in which you may reduce the amount of bytes allocates to your windows (not to worry it will refuse a number below used space on that partition) you'll have to try different numbers if you don't want to bother converting bytes to GB and don't worry, so long as you don't click on "install now" and subsequently confirm applying changes, nothing you mess around with in this screen will apply, so you can go back and start again as many times as you wish until you are sure you've set it up the way you want and then at long last you may click on "install now".

I personally recommend having a single partition with mountpoint / for your entire ubuntu in ext4 formatting (of absolute minimum 27GB) (max 100GB), one EFI partition of 650mb, (I'm guessing you have an uefi motherboard, (post 2015 motherboard)) and no SWAP partition.