How to set a coordinate system as default

1. Open a clean new drawing.
2. Set the desired coordinate system (Mapcsassign command)
3. Save the drawing as a .DWT
4. Use the "Options" command and expand the "Template Settings" located under the files tab.
5. Expand "Default Template File Name for QNEW".
6. Set this location to be the newly saved .DWT file.
7. Hit apply and OK.