what you mean? when you boot up with the current hdd with the data on it, you get a blue error message? well if thats the case, all you have to do is set the drive to a slave or a cable select drive, put it into another computer (thats working) and then transfer the data to the other computer harddrive. once finished you can format and reinstall windows or whatever.
if the problem is worse you may like to have a look at a data recovery software package to get the data. hope it worrks :grinthumb