[vivekair]

I am using an external HDD, with two partitions (NTFS).
I don't know what happened but the second partition is not working and the computer says it has RAW format.

Is there any way I can recover my valuable data?

[Elvandil]

The best thing to try first is to recover the partition. Testdisk is one of the best.

If the drive is mechanically sound and the files are not overwritten, than they are still there.

Free:

Testdisk Documentation
Testdisk Download
DriveRescue
Testdisk Boot Disk
Partition Find & Mount
Free DTIData NTFS Partition Repair Tool

Commercial:

Diskinternals Partition Recovery (Demo)
Active@ Partition Recovery
Bootmaster Partition Recovery
ZAR Partition Recovery
DIY DataRecovery DiskPatch
Partition Table Doctor
Nucleus Kernel Recovery for NTFS


Was the drive partitioned and formatted by you before use? Was it partitioned on a Vista machine?

[vivekair]

I Partitioned and formatted it using XP

[vivekair]

But I am using it on Windows 7

[Elvandil]

OK. Then there should be no problems with partitions being unrecognized. Try Testdisk first. You need to make some choices about which partition to restore, so you pick the one closest to size and location to the one that you lost.

Once you make that choice, you need to write the changes to disk. If you make a mistake, the files you are trying to recover will not be affected since you are only changing the partition tables. So you can still use recovery software later if you cannot obtain normal access. But Testdisk will almost certainly do the job. The Windows version is easiest. Read the documentation.

If you really can't use Testdisk, try Find&Mount. The free version has brakes on the recovery speed, but will still recover everything.

[vivekair]

testdisk solved the problem. thanx

[Elvandil]

Not too easy to use, but a miracle worker. Thanks for the followup.