DevConv can convert files among DXF-DWG-DXB formats, taking care of the preferred version. Managed version from R9 to R2007. This is a stand-alone utility, AutoCAD is NOT required. Easy to use interface, but also command line available to run it in silent mode.
What's new in version 1
ReleaseNovember 7, 2008
Date AddedDecember 29, 2006
Operating SystemsWindows 95, Windows 2000, Windows 98, Windows Me, Windows, Windows XP, Windows NT
Additional RequirementsWindows 95/98/Me/NT/2000/XP/2003 Server