External Hard Drive Not Functioning! Recover Files?
 

I have a NAS Device with a WD 400 GB Drive. The NAS device has not worked for the past two months and I'm guessing its the hard drive's fault. So I remove the external hard drive from the NAS and connect to my computer as an internal drive.

In Windows Disk Management I see the drive. It has 4 separate partitions on it. But I cannot see or extract any files from them. It says its not recognized file system type of something.

How can I recover data from the hard drive?

My guess is that the NAS is some sort of small Linux server and had the hard drive formatted in ext2/3. So, you'll need to use Linux to recover the files (a Ubuntu live CD would be perfect) or use some sort of software to read the partitions. A quick google search led me to this though I don't know if it's any good. Good luck.

In case the filesystems on the NAS are indeed of ext2 or ext3 format you can use this driver for Windows:
Ext2 IFS For Windows

I dunno if it's also working with ext4, but it works quite well for ext2 (and it's journaling variant ext3).