I followed the procedure and steps at the link to no avail. I have uninstalled and reinstalled Office as well as Project.
I am not having trouble downloading or installing the Project 2013. I am having problems activating the TRIAL version of Project 2013. Thank you.
The text of the error message:
Microsoft Project Professional 2013 Trial configuration did not complete successfully.
Error 25004. The product key you entered cannot be used on this machine. This is most likely due to previous Office 2013 trials being installed. (System error: -1073422306)