dualboot ubuntu13.10 and win8.1 already have 4 primary partitions

Question

I have a Toshiba Satellite L855-150 and I would like to install Ubuntu without erasing my Windows8.1 Installation.

The problem is I have four primary partitions on my laptop which are:

How do I proceed to install Ubuntu next to Win8.1 on my Laptop?

Which one of the four primary partitions can I erase to install Ubuntu?

Answer 1

You have more than 4 partitions, and none is contained in an extended partition. GParted shows six partitions. If any of them were logical partitions, GParted would show an extended partition container for them and, in the horizontal bar that graphically represents the disk, would show them physically inside that container. If this were a traditional partition layout, it would be invalid/impossible because it would mean you already have more than 4 primary partitions.

This indicates that this is not a traditional "msdos" partition layout--most likely it is a GPT partition layout, which is associated with UEFI as oldfred mentions.

In that situation, you are not limited to four.

So, go ahead and install Ubuntu.

• If possible, back things up first. At the least, make sure any important data (such as documents) are backed up.
• See Installing Ubuntu Alongside a Pre-Installed Windows with UEFI.
• See How do I install Ubuntu? and Install Ubuntu 13.10 for more general information.

Answer 2

AT YOUR OWN RISK -- I cannot under-state that

(option (a)) I see two partitions in the drive, /dev/sda5 and /dev/sda6. /dev/sda6 is probably for recovering Windows if it chokes -- as it is hidden. You could use that. It's pretty small but large enough to install ubuntu.

(option (b)) Boot with a Live CD and shrink that 585gb partition down (to half, maybe?) and install ubuntu in the unallocated space.

(option (c)) Get a larger drive (2tb?), copy the contents of your existing drive to it, and then install ubuntu.

Answer 3

Windows only ever allows 4 primary partitions, because the phrase "primary partition" is only applicable to MBR partition tables and MBR partition tables only allow four primary partitions.

In the above screenshot it was clearly shown that you had 6 partitions which exceeds 4,so it's not MBR.

In GPT partition table (available since Windows Server 2003 on 64-bit versions of Windows) you can have up to 128 partitions and do not need to distinguish between "primary" and "extended" partitions.

So you can erase any one of the partition other than the Windows partition and install Ubuntu on it.