Is There a Way to Remove the Restrictions Made by the Admin from the PC You Are Using?

I can't access the control panel. I can't access the command prompt and even if I do, there are specific commands that the admin has restricted so I can't use some of the commands in cmd. I can download files but I can't install those to the computer I'm using. And lastly, I can't access some websites like youtube and facebook. I know there are proxy servers but is there a way that I can unblock all the sited the admin blocked?