A drw to dwg conversion is typically related to attempts to transform vector data saved in one of the many known .drw files (vector drawings) to a .dwg file from AutoCAD.
It is likely that you can achieve this in several programs, but the success depends on the support for the particular type of .drw files you need to convert to DWG format.
Open DRW file Open DWG fileCreo Parametric (formerly known as Pro/ENGINEER) is a complete 3D CAD software solution by PTC
An old vector-based drawing software