MathCAD 15 3D not function

Seems to be an old/known problem - see this thread from 2010: http://communities.ptc.com/thread/32771

The poster solved the problem by uninstalling MC15, installed MC14 and upgraded to MC15 - by no means an desireable and accaptable solution.

The usual advice given here with problems with 3D graphs (uncheck border, reduce color depth, disable graphics acceleration in driver) seems not to apply here - it addresses problems with 3D graphs under Win7. See here: http://communities.ptc.com/message/153226#153226

There is one solution in the above thread you could try as it may apply to your problem, too and that is registering the glr.dll:

1. Go to Start>Run and type in cmd to bring up the command window (you should have Admin rights).
2. Type in the path cd c:\program files\Mathcad\Mathcad 15\ (or wherever Mathcad is installed).
3. Type regsvr32 glr.dll.
4. A dialog should appear that states it was successful “DllRegisterServer in glr.dll succeeded”.
This could fix the problem. However, each time Mathcad is uninstalled/reinstalled, you may need to register the dll again.