How to resize a Windows partition after Ubuntu installed?

Question

I have a new laptop which came with Windows 10. I managed to make it dual boot with Ubuntu 15.10. Unfortunately I left the Windows partition(s) too large when installing from a USB stick loaded with 64 bit 15.10. My hard disk, which does dual boot from grub has the following partitions:

The partitions 3, 4 and 5 belong to Windows I think, whereas 6 is my Ubuntu partition. Is there any (safe) way in which I could shrink/move the Windows partitions and make the Ubuntu one grow?

Solution

Boot from Ubuntu installation media - select Try Ubuntu without installing.

Open GParted (partition editor) - press the Windows key and type GParted.

Shrink partition 3 (Windows).

Move partition 4 to the left.
Move partition 5 to the left.
Move partition 6 to the left.

Grow partition 6 (free space)

Comments

[Sadi]

Isn't it a bit risky to shrink Windows partition like this, and wouldn't be safer to reduce its size from within Windows, and then do the rest from Ubuntu Live?

[cl-netbox]

@Sadi : It is recommended to not work on partitions from within a running operating system, so it is safer to do everything from a Live media, such as Ubuntu or GParted Live where all partitions are unmounted. :)

[NickT]

Thank you. Will the grub loader still be able to find the start of the Ubuntu partition in order to boot it? Also will Windows still start OK?

[cl-netbox]

@NickT : If nothing goes wrong during the operation ... both operating systems should boot as usual. :)

[NickT]

Excellent - thanks once again. All went surprisingly smoothly. Grub knew where to find the bigger Ubuntu OS and the shrunken Windows 10, if I should ever want it.