unrecognized disk label of a external HD

I also get this message when I try to mount the HD. I tried with and without the force option.

~ $ sudo mount -t ntfs-3g /dev/sdb /media/hd-ntfs -o force
NTFS signature is missing.
Failed to mount '/dev/sdb': Invalid argument
The device '/dev/sdb' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

~ $ sudo mount -t ntfs-3g /dev/sdb /media/hd-ntfs
NTFS signature is missing.
Failed to mount '/dev/sdb': Invalid argument
The device '/dev/sdb' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

Try these commands to repair partition table:

sudo fdisk /dev/sdb
w

Can you read this disk on another computer ?
If not, you could have to overwrite partition table (which is even more violent that format!).

I don't even know how to overwrite a partition table so I really hope I didn't so that. I have tried 3 different computers with no luck. Two xp computers and one Linux Mint computer.

For some reason I can now see my partition in Nautilus (my file manager) but I can't mount it.

When I do this command should which one should I be using?
sudo fdisk /dev/sdb
sudo fdisk /dev/sdb1

Also more information is showing up in sudo fdisk -l. The first time I tried it I couldn't see the part I am putting in between stars below.

~ $ sudo fdisk -l

Disk /dev/sda: 100.0 GB, 100030242816 bytes
255 heads, 63 sectors/track, 12161 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000c8b89

   Device Boot Start End Blocks Id System
/dev/sda1 1 1245 9999360 83 Linux
/dev/sda2 1246 5478 33998849 5 Extended
/dev/sda3 * 5479 12161 53681197+ 7 HPFS/NTFS
/dev/sda5 1246 1743 3998720 82 Linux swap / Solaris
/dev/sda6 1744 5478 29999104 83 Linux

Disk /dev/sdb: 203.9 GB, 203928109056 bytes
255 heads, 63 sectors/track, 24792 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x9503c6ab

**************************************************************************************************************************
   Device Boot Start End Blocks Id System
/dev/sdb1 1 24792 199141708+ 7 HPFS/NTFS

**************************************************************************************************************************

It now thinks I at least have a valid partition table.

System->Administration->Disk Utility
Select disk and click on button mount.
What happens ?

It mounts fine for me but I can't see the data. I know the data is still there cause I can see it with TestDisk. Unfortunately testdisk can only see the first 10 folders or I would backed up all my data that way.

Do you see any data ?
In this case, perhaps there is a user right issue at mount.
Type command
   sudo ls -a <mounting point of sdb>
What did you see ?

Neither of these worked.

~ $ sudo ls -a /dev/sdb1
/dev/sdb1
~ $ sudo ls -a media/26B085D5B085AC3D
ls: cannot access media/26B085D5B085AC3D: No such file or directory

sudo ls -a /media/26B085D5B085AC3D
with a slash before media

That doesn't work either.

~ $ sudo ls -a /media/26B085D5B085AC3D
ls: reading directory /media/26B085D5B085AC3D: Input/output error

Any other ideas please?

I had too many question to answers.
What's today status of your bug ?

My guess would be the partition table is messed up. I can't figure out a way to fix it. The HD won't mount. I recovered about 100 gb out of 160 gb of data with testdisk. The rest of the data testdisk can't see :(. I would really like to get the rest of the data off of the hd.

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

Delance do you have any ideas?

I read again whole thread. I presume the main sectors of NTFS file system were corrupted.
I'm afraid Testdisk, you already used, is your single solution.
What happened just before the problem occurred ?
Did you remove external disk without having properly unmounted it ? In this case, perhaps some critical file system sectors were not updated.

I was watching DBZ and really enjoying it. Then all of a sudden I couldn't access my external hd anymore. My computer then had a BSD. I hate windows. I was using it at the time instead of Linux.

My computer then had a BSD => the buffered disk sector in RAM where not written into external media, which is the same as removing key without unmounting.
Unix ext3 and ext4 file system have a journalling file which prevents file system to become unreadable when buffered blocks are not written into external media (but some new data can be lost). This process makes disk a little less efficient but more reliable.
From your issue, it seems NTFS chose efficiency.

The BSD happened after I couldn't access my data. I had 2 things happen. First I couldn't access my data. Then shortly after I had a BSD.

Does ext2 also have journalling? I've read it is a lot easier to recover data from ext2 then ext3 and ext4.

Any ideas of how I can recover my data?

I never used it, but lot of people use "testdisk" utility to recover lost data.
Ext2 has no journaling.

Have any more ideas of how to get my data back? I hope you do :).

Going back to the original problem since this direction you've looked at hasn't solved the problem.

Given the drive failed in use, I'd suspect the hard drive is no good anymore. If the drive has SMART technology, then booting from a livecd and running smartmon would give us a test report about the state of the drive.

The original post you made indicated no partitions are found, so I would consider using a data recovery tool that can read the raw sectors of the drive and attempt recovery.

How do I check if my HD has SMART technology?

What programs can look at raw sectors?

Using the Ubuntu Desktop cd, boot livecd (Try without installing I think the option is called).
Review this documentation for instructions on using and determining SMART.

https://help.ubuntu.com/community/Smartmontools

As for a data recovery tool, I use commercial offerings since this is a area I don't mess around with. There are several tools, and many free options may be more to your liking.

Good luck.