Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

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 am attempting to install Ubuntu on my machine since windows is messed up. I get this message and I am unsure how to proceed. I need some advice.


The installer has detected that the following disks have mounted partitions:


Do you want the installer to try and unmount the partitions on these disks 
before continuing? If you leave them mounted, you will not be able to create, 
delete, or resize partitions on these disks, but you may be able to install 
to existing partitions there.

In layman terms what does that mean?

I do not want to mess up anything on the hard drive or the system by installing Ubuntu. What should I do?

share|improve this question
This message appeared also in my installation process. I've quited the process of installation, restarted the PC, and started the linux installation agatin. And the message did not appear again. – androidevil Sep 14 '15 at 1:00
up vote 4 down vote accepted

"Mounting" means to make the disk or partition or data source accessible to the system. When you put a CD in the drive the operating system will mount that as a read-only data source with a drive letter assigned (in Windows, *nix OSes don't really use drive letters).

So what is happening is that the Ubuntu installer is seeing the partitions for windows mounted in such a way they cannot modify them.

You'll probably want to unmount the drive anyways regardless of what your end goal is.

You'll need to unmount the drive even if you want to keep your existing windows data and run the OSes side by side, or if you just want to save the data so you can access it. This will entail unmounting and then resizing the paritions so that you can make enough room to install Ubuntu.

share|improve this answer
So I should "unmount" the partitions and then proceed with the install? – L84 Aug 5 '11 at 21:21
Yes. Unmount is not the same as delete. The steps where you modify the partitions come later. – music2myear Aug 5 '11 at 21:23
I have tried to "unmount" and install yet the installation does not proceed any further. But I do have reason to suspect a hard drive issue so that might be the cause. Unsure though. Thanks for the help. – L84 Aug 5 '11 at 21:24

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.