I recently installed ubuntu 12.04 in virtual box. I dont know what the problem is but I dont get the button to instal in ubuntu software centre. It only shows "Use this source" button. Using sudo apt-get install results in "unable to locate package error. What to do?
First update all the repositories by running,
sudo apt-get update
Then try to install any packages via apt-get or sc. In a newly installed system, you have to update the repositories before trying to install packages or otherwise it shows the error unable to locate package. And also check for the package name is being correct.