Trying to use the unpacker took to unpack the various units as specified by the Kingdoms Units Addon for Retrofit mod...

and it says

"This application has failed to start because MSVP71.dll was not found."

What does it mean, and how can I fix it?

Also, how the hell does this thing work, anyway? I am computer illiterate. Can someone give me step-by-step instructions? Otherwise I fear I may break/ruin something:-X