Hi Rashmi,

You can install one package at a time. This error comes when you try to install two package a single instance.

To resolve this, close all the terminals first and restart the system. When you run the same command you won't any difficulty.

Hope this helps.

Thanks

I did close all theterminals and restarted it, and yet there seems to be a problem. But, now ubuntu 12.04 wont open in the vmplayer . The error that pops out is attachedd. What do i Do?