Hitachi HDD Failure

Hello all,

I am currently running a Hitachi HTS727575A9E364 HDD on my laptop. A day or so ago windows came up with a message after it had been booted up for a few hours while I was on it that Windows had detected a hard drive problem and that I should back it up and have it replaced ASAP. Strangely enough, after running a chkdsk /f on the drive I attained the following:

C:\Windows\system32>chkdsk /f E:
The type of the file system is NTFS.

CHKDSK is verifying files (stage 1 of 3)...
293888 file records processed.
File verification completed.
344 large file records processed.
0 bad file records processed.
0 EA records processed.
44 reparse records processed.
CHKDSK is verifying indexes (stage 2 of 3)...
388266 index entries processed.
Index verification completed.
0 unindexed files scanned.
0 unindexed files recovered.
CHKDSK is verifying security descriptors (stage 3 of
293888 file SDs/SIDs processed.
Security descriptor verification completed.
47190 data files processed.
CHKDSK is verifying Usn Journal...
34894792 USN bytes processed.
Usn Journal verification completed.
Windows has checked the file system and found no problems

732469247 KB total disk space.
90356048 KB in 211877 files.
120884 KB in 47191 indexes.
0 KB in bad sectors.
417175 KB in use by the system.
65536 KB occupied by the log file.
641575140 KB available on disk.

4096 bytes in each allocation unit.
183117311 total allocation units on disk.
160393785 allocation units available on disk.

As windows states approximately halfway through the log, there were no bad sectors on the disk and it detected no problems. I find this strange because when I ran Western Digital's DataLifeguard on the disk it passed a quick test just fine, however during the extended test it ran for approximately 1.5 hours before coming back and telling me that the check could not be completed due to too many bad sectors being present. This did not have an error code accompanying it, just that message.

Additionally, I ran HGST's WinDFT (drive fitness test) on my drive. A quick test came up with a pass, while an extended test gave me a 'Read Element Failure' and a failure of the test as well.

Also, all the driver diagnostic software I have used so far have reported all the stats on my drive to be at acceptable levels and confirmed that the drive is healthy. Currently the drive is plugged into an empty bay on my desktop where I have ran these tests and type this.

Very little of the total space on this disk is currently in use, I just finished writing the disk to 0's and fresh installing windows just a couple of weeks ago and these same tests told me that my drive was fine at that time. The drive has performed good as new ever since that time with no errors occurring and even after/around the time of the error report by windows, the drive still seemed to be functioning perfectly fine.

My questions:

1.While I will probably do this anyway and clone my current HDD over to it, should I replace this HDD?
2.Why does chkdsk /f reveal no bad sectors when extended tests tell me that they can't finish even a small portion of the check without running into too many to continue?
3. Tips to diagnose further or determine if the drive is still viable to use?
4. Is the 'read element failure' reported by the WinDFT test akin to too many bad sectors on the disk as reported by WD's DL?

Thank you for your time. Any insight or help is appreciated.