while following one of the tutorials I needed to install a curl package. Here are my system configuration:

Virtualbox 4.1 on Windows 7 64 bit. I have installed ubuntu 12.04 on the virtual box.

When I try the following:

sudo apt-get install curl

I see the following errors:

[sudo] password for userMe: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package curl is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'curl' has no installation candidate
userMe@userMe-ubuntu:~$ 

When I try the same on a direct installation of ubuntu on a laptop (not a virtual machine) there is no problem.

I am assuming this may be because of network settings. Please note that my work PC is in a corporate network and uses auto proxy settings (using a .pac file) for internet access etc.

Any help will be appreciated.