Thanks to user JWatt who discovered that if you have multiple Office products bundled in the same directory (standard, pro, enterprise, etc.) and you execute
setup.exe /adminfile your_msp.msp
from within PDQ Deploy you will see the error:
File not found on target computer.
When you attempt to install manually by running the setup from a command window you will get a dialog which asks which Office product you are attempting to install.
RESOLUTION: Only have the version of Office (standard, enterprise, etc.) that you wish to deploy in the source directory from where you execute setup.exe.