Many CAD users change the aliases of common commands in the ACAD.PGP file. The location of this file has been moved around over the years and finding it has always been a problem.
The quickest way to access the PGP file is within AutoCAD.
1. Tools pull-down menu
2. Customize
3. Edit Program Parameters (acad.pgp)
This will open the file within Notepad. All you have to do is make modification to the command aliases.
For example, many people change the COPY alias from CO to just C.
Note:
1. You cannot have two alias with the same letters. For example, you cannot use C for the COPY and for the CIRCLE commands.
2. Any changes made to the PGP file will only take affect aftere restarting AutoCAD.