I've been trying to change the target for My Documents from the C drive to
the D drive (someone partitioned my harddrive).

I wasn't allowed to do that at properties of My Documents. I then changed
the value for DisablePersonalDirChange under RegEdit. That did not help.

I then deleted the DisablePersonalDirChange key. That did the trick (but
only for a day). After I rebooted, the key was still gone and the target
change still ok. However, when I got back the next day (after another
restart), the target for My Documents was back to the C drive.

The DisablePersonalDirChange key is still gone and I could go back to the
properties of My Document and make the switch from C to D again, however, I'd
prefer a permanent solution.

Any thoughts would be appreciated.

Thanks.