Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm attempting to install Ubuntu on my laptop to dual boot with Windows 7.

I have a single 320GB hard drive with the following breakdown:

sda1 (fat16) 41.1  MB (not sure what this one is for)
sda2 (ntfs)  104.9 MB (not sure what this one is for either)
sda3 (ntfs)  64.4  GB (Windows 7 is installed here)
sda4 (ntfs)  220.0 GB (Separate partition where I keep photos, music, etc...)
free space   35.5  GB ("unusable" ???)

I was planning to install Ubuntu on those 35.5 GB of space, but when attempting to do so it says that the space is "unusable". It won't let me format or do anything else with it.

What can I do?

share|improve this question
are those partitions primary or extended ? Cause in ms-dos format table you can have only 4 primary – Denwerko Jul 21 '11 at 14:30
up vote 3 down vote accepted

Likely you have four primary partitions.

To rectify this, you would need to remove a partition, replace it with an Extended Partition, then use logical partitions within that Extended Partition to get more than 4 partitions onto the drive.

share|improve this answer
I used the free Partition Wizard to change the sda4 partition from Primary to Logical instead of removing & replacing - took only a few seconds. Installation is now underway. Thanks! – Michael Moussa Jul 21 '11 at 15:12
Was still the same issue. Regardless of the cause, if the answer helped solve your issue, you should mark answers as the solution then. – Thomas Ward Jul 21 '11 at 15:13
I did... hours ago. – Michael Moussa Jul 21 '11 at 21:05
how to do this? – anshupitlia Apr 4 '15 at 10:25

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.