Norton Power Eraser and sound problem

Due to slower than usual reaction to anything on my laptop (even after deleting cookies, defragmentation and checking for any unneccessary programs that could cause it), I've decided to run Norton Power Eraser.

After restart, I cannot play Youtube videos (I have Java and Flash, there was nothing wrong with playing them before) and there's no sound on my computer. It has built-in speakers. I did not plug any other devices. I've already checked everything I could from Microsoft Support Page. System itself can't find any solution and the tool for solving problems with sounds cannot find any either. It says that I do not have any speakers. Nothing chnges when I plug in headphones. No sound either, nor does it see them.

(I'm sorry for my lack of technical knowledge and any mistakes in English!)