I have been playing with getting ArcGIS set up in AutoCAD 2012 for two days now.
Here are the steps I use:
1. Run CAD as Administrator
2. Type "NETLOAD"
3. Select ArcGIS250 "dll" file.
The ESRI/ArcGIS250 window pops up and then disappears, but it is nowhere to be found. I am runninbg AutoCAD in Classic mode, I have switched back to Drafting and Annotation mode as well, and am not able to find the tools to utilize ArcGIS. I am really at a loss... Any help would be greatly appreciated.