If your installation has already been impacted by a malicious application or routine that runs on startup, following these general steps: 
- Run your anti-virus checker. All leading anti-virus solutions identify and repair AutoCAD virus infections. 
 
-  Start your AutoCAD-based product using the /safemode command line switch. 
 
-  Find and remove all malicious code. This process is made more difficult if you had been running as an Administrator with User Account Control (UAC) turned off. As a result your AutoCAD install folder might be compromised as well. 
 
-  Repair any affected files. 
 
- Set the SECURELOAD system variable to 1 or 2. 
 
- Set the TRUSTEDPATHS system variable to unique, read-only folders. 
 
- Remove the /safemode command line switch from the command line parameters.