Adprep was unable to copy setup files from installation point to local machine. Status/Consequence Adprep has stopped without ...

Adprep was unable to copy setup files from installation point to local machine.
[Status/Consequence] 
Adprep has stopped without making changes.
[User Action] 
Make sure you run adprep.exe under the directory that contains the following files: schema.ini, sch*.ldf and dcpromo.csv. The recommended way is running adprep.exe from installation media, such as CD-ROM or network share. Check the log file ADPrep.log in the %1 directory for more information.