I installed the compiz settings manager, to try out some effects. But after installation i felt something unuseful and dragging the system speed.So, thought of removing the app. using terminal. And this is what happened the terminal and other applications take large amount of time to get opened,maximized, minimized,closed. Removed the settings manager, still the problem exists.
This would be a very strange behaviour for compiz to say the least (standard values are not supposed to break your system, custom values are...), so I doubt that your problems are related to compiz (alone).
But assuming that ccsm is indeed the culprit, I'd suggest to simply reinstall it, reset it to standard settings, log out and in again. If that didn't help, you can always purge the application, meaning that not only the application itself but all its settings as well are deleted.
Finally, still on the supposition that your problem relates to ccsm and that nothing of the above helped in any way, you can simply try to configure ccsm to function properly, like e.g. described here.
Good luck to you and best regards!
Open the System Monitor app from the Dash Menu. In the Processes tab, you can see if there is any program that is using all the memory of your computer.