Question : Problem: SATA Drive lost data all of a sudden. Recovery?

Hi,
A bunch of important info has mysteriously disappeared of a SATA Hard Drive.

Scenario:
Dell Workstation needs to have windows reinstalled. The original SATA hard drive with all the data is unplugged and left secured in the PC case. A new hard IDE Hard Drive is installed and the new operating system is installed.

When the original SATA drive is plugged back in much of the data is missing. The drive still boots windows but the users folder / my documents / desktop is missing.

Originally there was about 50gb of data, now about 16gb.

We are running GetDataBack NTFS from runtime.org and it has picked up some folders but I dont think the user's data is amongst it.

What else can we do?
What could have caused this?

Regards
Smitch

Answer : Problem: SATA Drive lost data all of a sudden. Recovery?

We never figured out what happened. Ended up loosing the data.

Thanks for your input