My hard disk check failed?

well i did that on mt pc on a 250 gb sata disk, it failed but it still works. when your hard drive is going to go for sure your pc will tell you. this happened on my acer once (last pc) i got a message before boot S.M.A.R.T ON HARD DISK C IS ABOUT TO GO PLEASE BACK UP ALL DATA PRESS F1 TO CONTINUE if i pressed f1 it worked as normal so don't worry about it. and when you do get this message get a NEW hd then download norton ghost and it will copy your old hardrive to new so you don'thave top reinstall windows and you will have your data still