Most of the time you will probably replace a computer before your hard drive stops working, but if you let them run long enough every hard drive will eventually crash, fail or die.
There are 3 types of hard drive failure you have to concerned about.
First, there’s a physical problem with the drive. The most common things that fail are the PCB board (the chips or power connector on the board), but there are dozens of moving parts in a typical IDE or SATA hard drive and they can all fail. I explain this kind of failure in more detail here. Symptoms vary. If there’s certain physical damage you may hear a loud clicking noise. Sometimes if the heads are stuck on the platter you’ll hear more of a buzzing or beeping noise. Or if the power connector is damaged, you may hear nothing- no spinning, no whirring- and the drive may not be seen by Windows at all.
Your hard drive can also crash if it has too many bad sectors. Sectors are small clusters of storage space that hold your data. When a sector goes bad, software on the drive is supposed to try to move the data to a good sector, and mark the bad one so it never gets written to again. In some cases, sectors can become so damaged that the computer can have trouble reading the data, lock up, refuse to boot or crash.
In this example, the hard drive shows problems with the reallocated sectors count, the current pending sectors count and the uncomfortable sectors count. Each variable has exceeded the allowable threshold, so the data on this drive needs to be backed up right away.
The second possibility is called logical failure. This is not a problem with the physical drive itself but with the file system on the drive.
Imagine your hard drive is a library, and your files are the books on the shelves. Your computer has its own version of a card catalog to find your files, called a File Allocation Table, or FAT. Saving changes to your FAT is one of the things Windows does when we shut down or restart the computer. If the FAT is corrupted, Windows can’t find the files it needs to run the Windows Operating System, and you will be unable to boot your computer.
Just like the books will still be on the shelves in a library without a card catalog, your files should remain intact on your hard drive even with a damaged FAT- your computer just doesn’t know how to find them. This can be caused from a virus infection, system driver conflicts, damaged Windows files, bad Windows updates and other software issues.
If this is the problem, in most cases I can perform a Level 1 data recovery to get your files back. The files can be backed up to a good hard drive or flash drive, then your hard drive can be wiped and reloaded with a fresh version of windows with a new FAT. Then I can transfer your files back over to your new Windows installation. I can backup any user created files (photos, documents, music, videos, etc) but not your programs – I would need the software and licensing information or serial numbers to reload your software.
External hard drives are susceptible to physical and logical issues as well, but they also have a potential problem that doesn’t exist in internal hard drives. External drives are really just an internal hard drive in a fancy enclosure so you can connect them with a cable and move them around from place to place. The enclosure has its own power supply and data connector and sometimes these connectors die or break after dropping the drive. In that case, the hard drive inside may work perfectly and the enclosure may be the issue.
With all the different ways your hard drive can fail, this is a good time to remind you to always keep an updated backup of your files. Spending $100 on an external hard drive or a cloud backup service can save $1000 in data recovery fees, so backup, backup and then backup again.