I followed the suggestions from the previous thread I found a page or two back. Going into graphics setup and setting it to OpenGL and running as admin didn't resolve the issue. At a loss at what to do next

There's nowhere near enough information here for anyone to help you.
Please provide your system specs (CPU, RAM, GPU, etc). Also let us know whether you are using the provided DosBOX or some other engine (e.g. eDuke32) to run the game.

Configure The Duke Nukem 3D shortcut to have Run as Admin Checked for all users. if you can post a screen shot of the error. is it a windows error or is it a dos error.

duke3d works for me on win 7 64 bit with the default settings.
have you tried reinstalling it?

some Windows installs block dosbox from letting duke3d.exe load its config files if Ruin as admin is not checked. this may have been fixed in a later install package.

I have Xin7 x64, and mine crashed on startup until I set the link to launch in WinXP (SP3) compatibility mode. (It then asked for permission for dosbox.exe to make changes to the machine, so run as admin would also probably have worked.)

Worked like a charm with my Win 7 machine. Needed a restart after the changes and away I go! Thanks Jeff.