I have an imac computer and i accidentally deleted the system preferences!!!! what do i have to do to get them back? its really important cause my mom is gonna kill me!!!!!!!!!!!!!!

Wow.

Did you actually drag the System Preferences icon to the trash can? Or did you just change the settings?

I've never done anything like this before, but I would think you can go into your Time Machine and just restore the backup image when your System Preferences were still on your machine.

Hopefully, you ARE using Time Machine, so I would think this wouldn't be a problem.

Hope this helps.