Deleted my cookies

Hello,
I ran a program called CCleaner and it deleted my cookies...but does deleting your cookies cause

Download to be unsuccesful, cause it says it can't access some sort of server

and Not able to check E-mail or watch videos...except when the video is posted onto a different domain.

Or Make Mozilla FireFox not work.



I once deleted a virus, A vundo trojan, but these Internet Explorer symptons happened after I deleted it...

So does deleting cookies cause this?