Reformatting after a magnet attack

May 19, 2006 6:14 AM

I found a magnet hiding under my PC yesterday. Now Windows is telling me that my second hard drive isn't formatted, but it's unable to format it when I try to do so. I don't care about the data on the drive, I just want a useable disk again! Any suggestions?

Running on Windows XP. The unformatted disk is making Windows freak out a little bit, programs that would normally be accessing data on that drive (it's used to store music, movies, games, etc.) and Explorer are running very, very slowly. I'd rather try to fix this myself than take it into a computer shop. Thanks!

posted by billybunny to computers & internet (9 comments total)

You might be able to use this program called fdisk to format the drive if you can't do it in Windows Explorer. Windows may also come with a utility that is just for formating and partition hard drives, I know Mac OS X does.
posted by chunking express at 6:29 AM on May 19, 2006

from what I read on one of those debunking pc common myth sites magnets do not generally harm regular hard drives. I would try formatting it with one of the tools on the ultimate boot cd
posted by psychobum at 6:33 AM on May 19, 2006

i would check out GParted live CD (GNOME Partition Editor) it has an impressive list of features
posted by phil at 6:42 AM on May 19, 2006

goto control panel -> admin tools -> computer management.

then under storage -> disk management

you can right click the drive and do whatever you want with it.
posted by moochoo at 6:49 AM on May 19, 2006

partition magic may help. alternatively, pop your windows install cd in, boot from that cd, and use that tool to format the drive. DO NOT install windows on it.
posted by shmegegge at 7:33 AM on May 19, 2006

With due respect, all of the above are standard high-level format options, including fdisk, Windows NT partitioning, Partition Magic, and the Computer Management snap-in.

To do truly low-level work, you usually need the manufacturer's utility built for this work. So, we need to know the manufacturer.

You could concievably find out the manufacturer by looking at the drive model in Device Manager, but you'll want to crack the case eventually anyway to pull the power from the other drive that you don't want to accidentally format.

If the drive is from any of the big three (Western Digital, Seagate, Maxtor), then you should be able to get the manufacturer's drive utility image from their website and create a bootable floppy with it. Generally the utility download is an EXE and will create the floppy for you.

As I said, open the case and physically pull power to the drive that you want left alone. Yes, the utility will give you a choice of which disk to work with, but I always find it's best not to give myself the chance to screw it up.

Then boot to the floppy, and run basically every operation the utility offers. If the hard drive won't format after that, then it's time for an RMA. If it's out of warranty, then it's time to break out your Torx drivers and really get to know how a hard drive works.

But don't pinch yourself with those magnets!
posted by SlyBevel at 8:45 AM on May 19, 2006

The operation that the manufacturer utilities call a "low-level format" these days is simply writing zeroes to every sector on the drive. Proper low-level formatting has been a factory-only, manufacturing-time operation for at least ten years.

You can do this yourself with Linux:

dd if=/dev/zero of=/dev/hdb bs=1048576

This command will work on any of the tiny Linux distros that boot from floppy or CD-ROM (I'm pretty sure dd is there in every Linux distro ever made) provided you're logged in as root.

This assumes your second hard disk is the IDE primary slave. If it isn't:

/dev/hda is IDE primary master
/dev/hdc is IDE secondary master
/dev/hdd is IDE secondary slave
/dev/sda is SATA drive 0
/dev/sdb is SATA drive 1

Once the drive is blanked, do what moochoo said.

The only point of writing to every sector is to force the drive to relocate any bad sectors that are pending relocation. If your magnet was powerful enough to damage the data on the drive, it's probably damaged the embedded servo information as well; there's no way to fix that. But it would have to have been a hell of a magnet.
posted by flabdablet at 10:06 AM on May 19, 2006

Fersure do not attempt to do any low-level formatting of your drive. You are far, far more likely to end up destroying the disk permanently than actually resolving any problem.

You may have best success by booting a Knoppix or other Linux/BSD CDROM and using the partition manager they offer.
posted by five fresh fish at 3:52 PM on May 19, 2006

Thanks for the suggestions everyone. Unfortunately, I seem to have screwed the damn thing up even more than it was. Now the PC won't boot (into either Windows or Linux-on-a-disc) with the second HD plugged in. Taking it out makes everything peachy, though.

I started up a disk management format and the machine locked up. After that it wouldn't reboot, just hung at a blank screen after telling me that the disk is bad. I'm going to take the HD into one of the 35 computer repair shops (a benefit of living in a college town) tomorrow and see if they can salvage the it. I'm also gonna start scavenging around for those warranty papers...

(For those who were curious, I found a magnetic strip [I believe from the door of a refrigerator] sticking to the bottom of the tower. Right underneath the HD. I put two and two together, but it could have been something completely different for all I know.)
posted by billybunny at 5:54 PM on May 19, 2006