I have a problem. Whenever I turn on my other computer it says: "A disk error occurred" and I tried to insert a system recovery disk into the computer and I waited for hours but nothing worked. The computer screen is black after I press "ctrl + alt + delete" even though the text suggested that. I can't access my files, I can't go on the internet and I can't go to desktop view. How can I fix my computer without having to pay money?