I first had windwos 7, then I installed Ubuntu alongside and when my laptop starts I can choose between ubuntu and windows (the ubuntu boot screen) .
Now I have installed another ubuntu inside the windows 7 using virtual box. I want to remove that first ubuntu installation and free up its partiotion. Can I do it without making any problems for the windows and boot screen?
You should try OS Uninstaller, that can be used from a live usb, burned into a CD or installed on your Ubuntu.
Open the Terminal (Ctrl + Alt + T), then type:
sudo add-apt-repository ppa:yannubuntu/boot-repair
Press enter and then type:
sudo apt-get update; sudo apt-get install -y os-uninstaller && os-uninstaller
The OS-Uninstaller will be now available, so open the Dash Home and type OS-Uninstaller, then press enter to initialize it.
For information on how to use it access the official article at Ubuntu Documentation (https://help.ubuntu.com/community/OS-Uninstaller).
If you used the windows installer from Ubuntu then it can be uninstalled via Control Panel\Programs\Programs and Features
