Andrew's hard drive is starting to make a ton of noise. Leo says that's a sign that the hard drive is failing, and he needs to get the data off it and get a new hard drive. If the hard drive can't be read, Andrew has heard that he can freeze the hard drive and it'll make it run temporarily. Leo says it's a last resort and may just work, but he shouldn't be surprised if it doesn't. This is why it's so vital to backup.
Andrew could probably take it to DriveSavers to get the data off. They take apart the hard drive and put it in a new housing, but it can cost thousands.