Ok I'm trying to use a CD disk but when I put it in it keeps saying D:/ is not accessible?

check if its not a DVD burner.. like they should open CD's too... but sometimes the bugger up and wont accept them..its coz they are primarily made to burn DVD's not CD's.. if thats not right... just try shutting down the comp and leaving it for 5 mins.. if that doesnt work im not sure.. we get the same problems too but those 2 things usually work.. the security settings shouldnt really effect it..