WD SATA Drive reporting a logical drive on un-partioned HD

Running XP Pro, and WD 5000AADS SATA as un-partioned C: drive.

 WD Lifeguard reports C: as a logical drive with only 90GB capacity.  Lifeguard reports the drive as error-free.  Where is the other 410GB?  The drive was never partitioned, and Lifeguard does not report any other logical drives, just C:/

XP properties for C: also reports 90GB.

This is a recent problem…C: properties was always reported by XP as 500GB until last week…no hardware/software changes were done recently, except some auto-installed updates from Microsoft.

I have always run free AVG and paid Malwarebytes, so I doubt it is a virus/malware issue.

Suggestions needed-

thank you.

Welcome to the Community.

Did you try searching for clues within Windows Disk Management?


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This is getting really weird…The instructions in that link didn’t work, no disk Management selection showing, but I was able to access it via the RUN command compmgmt.msc.

XP Disk Management is showing the problem, I think:

It shows two partitions for C:

One at 90GB, and the other, Named “Acronis SZ” at 376GB (Unknown Partition).

I do use Acronis for imaging to a NAS drive for complete backups, but don’t understand how this hidden C: partition got created…if you screw-up the Acronis and specify the destination as the same as the source drive, you get a pop-up error,

And I’ve been using Acronis for a decade, and wouldn’t make that error, unless I was really out of it (possible!).


I’ve gone to the Acronis site, and there is conflicting information on how to delete this hidden partition, depending on operating system and version of Acronis that created it.  The big problem is how to un-partition the drive without a reformat…

The “SZ” is Acronis “Secure Zone”, but why they would put it on the source drive is beyond me, and the partion size automatically grows with increased Acronis use, and remains hidden to most disk utilities.

The contents of the SZ partition can be deleted from within the Acronis toolbox, but apparently doesn’t eliminate the space allocation and return C: to a single volume.  That’s all I know so far.