how to delete other operating system windows7 present along with ubuntu

Did you use Wubi?

On 12/31/2011 06:45 PM, actionparsnip wrote:
> Your question #183380 on nautilus in Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+source/nautilus/+question/183380
>
> Status: Open => Needs information
>
> actionparsnip requested more information:
> Did you use Wubi?
>
> ya i use wubi.............

this becomes a bit more complicated. Wubi uses your windows partition to install Ubuntu.

http://en.wikipedia.org/wiki/Wubi_%28Ubuntu_installer%29
"While Wubi does not install Ubuntu directly to its own partition this can also be accomplished by using LVPM, the Loopmounted Virtual Partition Manager, to transfer the Wubi-generated Ubuntu installation to a dedicated real partition,"

Meaning that in order to remove windows from your wubi install would be very technical, though possible. see
https://wiki.ubuntu.com/WubiGuide
look under "how do i migrate to a real partition.

My personal opinion would be to backup your important files from both sides, download the ubuntu desktop iso and install using the full hard disk drive. during the install you can format the entire drive to remove windows and use the ext3 filesystem (linux file system). See https://help.ubuntu.com/community/GraphicalInstall around step 5 for an example.

Don't use LVPM - it doesn't work on Ubuntu since release 9.04.

In the Wubi guide referenced by "Nathan nolast" there is a link to a more recent script. If you want to completely replace Windows, it's easier to just backup your data and install from a CD/USB over the whole drive. If you have a lot of customization on Wubi that you want to keep then the migration can preserve that.