This error indicates that the setup executable is unable to determine where it should be installing the Partsmart-related files. To correct this problem, search the contents of the PartSmart CD-ROM for a file called Pathingtool.exe. This utility will allow you to set the install location for PartSmart.
If you are unsure of the correct install location and need further assistance, feel free to contact ARI's Client Services department @ 1-800-558-9044.