I need computer help because i stupidly deleted something important from it T.T?

I was cleaning out my laptop manually and i didn't realize but something i deleted made it so that i can't download anything from the internet. Usually when you click to update something or download something, a bar pops up in the top that you have to click to download the produce, well that doesn't pop up for me either. I also go on facebook to play a game and when i click the game it just shows a blank white screen where the game is suppose to be. It doesn't tell me to update my adobe player and even if it did i can't :( i can't download anything at all and when i try it tells me this "Internet Explorer was not able to open this internet site. The requested site is either unavailable or cannot be found. Please try again later." well it can be found and theres nothing wrong with the link given to me it just wont wallow the download. Can anyone tell me what i might of deleted to have this happen to my laptop??? plzzz i rly need to fix this cuz my mom is using my school laptop to play her damn games and i need it for school T.T