Failed to save license to file when applying registration file for Contractor

I am trying to install Contractor 6.1 for a training class we have scheduled later in the week.  When we try to load the registration license file that we downloaded from http://www.oracle.com/us/support/licensecodes/primavera/index.html, we receive the message "Failed to save license to file C:\Program Files\Primavera\registration.ldf"

We found solution ID 904067.1 which references this error, but we are installing Contractor on XP, not Win 7 or Vista.  Any ideas how to solve this problem.