Powerpac not loading

I'm sure this more an issue with my own machine than it is the program but if I click on any Toolbook on my local drive I get the error message below. The book then loads but with PowerPac functionality.
"The file C:\program\PgsdTo\PGSD_P ....SBK. could not be loaded or is not a valid system book."
"The file C:\program\PgsdTo\PGSD_P ....SBK. could not be loaded or is not a valid system book."