In some cases AutoCAD 2015 may refuse to start, and returns an error code of 0xc0000142. This seems to be an exceedingly rare problem that may be caused by the Adobe Acrobat 9.5.x Extended Web Capture module.
An article from Up and Ready suggests using a SysInternals tool called Autoruns for Windows to systematically rename each AppInit DLL individually until AutoCAD starts. In an update they also describe how to make the change in the registry, but warn that some applications may change this back when they start up.
- Download Autoruns for Windows.
- Start Autoruns for Windows and Click on the AppInit tab.
- Rename each listed DLL, one at a time, and attempt to start AutoCAD.
- Repeat until AutoCAD starts successfully.
Renaming may disable the AppInit DLLs, so be sure to rename them back to their original names if they prove not to be the cause of the AutoCAD problem. Alternatively, if you made the registry change listed in Epilogue III of the linked article, other applications that may want to use AppInit DLLs may reset the registry setting when they are started.