disk read error

I have had my computer shut off for about 3 months and I turned it on today and i got the message “A disk read error occurred, press Ctrl+Alt+Delete to restart” I did that and I keep getting back to the same thing when it restarts. I can not do anything other than get to that page. Does anyone have any ideas on how to fix that? I am very computer illiterate so make it easy on me.