I'm unable to install any of the programs from Ubuntu Software Center. It constantly stays at 0 % with the following message: 'Waiting for other software manager to quit.' How could I solve this problem?
Do you have synaptic or the ubuntu software center open?Have a look under processes.
To see running processes goto System-->Administration-->System Monitor
Search for the processes that says apt-get or synaptic.If you find any process,select the process and click End Process.
If no process were running but still if you cant install any packages then type the following in terminal..
sudo rm /var/lib/dpkg/lock
This will remove the lock,now you can install packages..
Also See this post
It is likely that you have a terminal process or synaptic currently "in charge" of installing software. Ubuntu stops new programs that are in charge of installing/removing/updating software from starting when there is an existing application/process that has the same function. You probably just need to wait for an application you were previously using to close/relinquish software changing rights and/or close that process if you have not already done so.