Windows 7; deleted several programs. Cant access anything

Ive turned my computer on and it made the de-dun sound (sorry) and came up with an error message, saything that something couldnt open as I didnt have permission.
Its actually deleted the internet explorer icon, and wont let me access things like computer or any files. It also wont let me access specific files such as iTunes, Spotify and internet explorer. Again saying that i dont have permission. I have managed to get my anti malware program running, but that doesnt seem to have done anything. Are there any other suggestions as to what could be done to sort it out.
Thanks for any feedback!!