删除ddeexex以及调整dwg文件的默认打开方式为AutoCad Launcher
Windows Registry Editor Version 5.00
[-HKEY_CLASSES_ROOT\ACAD.B001.804\shell\open\ddeexec]
[-HKEY_CLASSES_ROOT\AutoCADDrawingInterchange.19\shell\open\ddeexec]
[-HKEY_CLASSES_ROOT\AutoCADDrawingStandardsFile.19\shell\open\ddeexec]
[-HKEY_CLASSES_ROOT\AutoCADSheetSet.19\shell\open\ddeexec]
[-HKEY_CLASSES_ROOT\AutoCADTemplate.19\shell\open\ddeexec]
[HKEY_CLASSES_ROOT\AutoCAD.Drawing.19\shell\open\command]
@="\"C:\\Program Files\\Common Files\\Autodesk Shared\\AcShellEx\\AcLauncher.exe\" /O \"%1\""
Win8.1 AutoCad2013 x64双击文件打开错误解决办法
原文：http://www.cnblogs.com/marineturtle/p/4018837.html