Anyone who uses Vista knows what I mean. I assume there must be a reason D3 is set to run in admin mode, but I can't figure out what it is.
Out of curiosity, I set it to NOT run in admin mode, and it *seemed* to play fine. Anyone know why?
Of course, Vistas heuristics may have automatically set it to run that way and GoG had nothing to do with it.

have you also notice that D3 installs a weird entry along with it in the list of add/remove programs? i seriously don't know why it does that?...click in the attachments: below.

That's obviously a minor bug in the GOG version because this entry doesn't appear when installing from the distribution CDs.
You can also give this one a go:
http://www.dateiliste.com/en/descent-3/26-descent-3-installation-updates-and-modifications/120-download-the-full-version-of-descent-3.html
It only needs to run as administrator during the installation.