Originally published at: http://www.howtogeek.com/173463/bad-sectors-explained-why-hard-drives-get-bad-sectors-and-what-you-can-do-about-it/
A bad sector on a hard drive is simply a tiny cluster of storage space — a sector — of the hard drive that appears to be defective. The sector won’t respond to read or write requests.
If you have reason to believe that bad sectors or a failing hard drive are the cause of your computer problems, which they could be as they can manifest themselves in many different ways, another good tool to have on hand is a copy of SpinRite. It performs drive scans on different levels such that, very often, data can be recovered, or the machine can boot properly again. Of course, no software can perform miracles, but in many cases, it will look like SpinRite did just that. Just a thought, as I have used it in the past, with great results, and it is often underrated tool.
'For example, if your computer suddenly shuts off due to a power outage or a pulled power cable, it’s possible that the hard drive may have shut off in the middle of writing to a sector.'
My PC doesn't shut off immediately but shifts to battery. When the battery drains, that's when my PC shuts off.
Not all PCs are laptops. I do have my desktop connected to a UPS, however, that will shut the computer down safely in case of a power outage but the desktop is still susceptible to a pulled power cable. Even a laptop could suddenly shut down if the battery dies prematurely (happened to me on a netbook once).
This is interesting. I think my HDD is suffering from bad sectors. I installed some beta GPU drivers and they started to glitch out, I had made a restore point so I decided to use it (bad idea as it only restored my SSD and not my HDD) it was freaking out worse (anti virus froze immediately etc) so I did a system refresh.
I had taken out my GPU and a stick of RAM just in case so after installing some programs, I decided to shut down and put my GPU and RAM back in. When I booted up, I got the "Checking Disk for errors 0%" for my HDD.
I let it sit for over 30 min and it didn't move an inch. I used my Linux flash drive to check on it and it wasn't recognizing it saying that the HDD wasn't mounted (turned out it was because I had fast boot on.) I shut down and let it scan over night. Still nothing. I finally managed to skip the check and start backing up more files than already on my backup.
I then went into the HDD's properties and tried to disk check it from there, immediate error. I used WD's software to check, immediate error. I started thinking it was a bad sector but I still wasn't sure. I went into Program Files (x86) through my Linux flash drive and it wouldn't even load. Kept saying a firefox file was corrupt. That is when I knew.
Thankfully I have warranty and WD will send me a new one for free
Thanks for the tip Barnett. I'll try SpinRite.
You read my mind Lady F. It happened with my netbook -- many times.
I second the SpinRite software. I have used it since version 2, back in the 1980s. It is arguably the best consumer level hard drive recovery software on the market.
If you are just trying to recover data from a hard drive, and don't plan to use it later for storing valuable data, it has been said that freezing the hard drive in an air-tight bag sometimes causes the data to be recoverable. YMMV.
Even better is to have a good backup scheme in place so, if a HDD goes to computer Never-never Land, you don't have to worry about recovering data from the dead drive, an iffy process at best; just recover from the backup. If one doesn't have their data in at two or three places (the more, the merrier), then the data might as well not exist.