This article explains the cause of BarTender issues relating to a missing Adobe Reader after software installation.
Immediately after installing BarTender, the BarTender installer attempts to open GSMEnu.pdf. The “Getting Started with the BarTender Application Suite” is an introductory manual saved in PDF format. If Adobe Reader (or other PDF reader) is not installed and associated with .pdf file type, Windows prompts the user to locate the application (e.g. Adobe Reader) that can read this file.
Proper install procedure has Adobe Reader as a prerequisite. If Adobe Reader was not installed prior to BarTender installation, Adobe Reader can be installed at a later time with no consequence to the ability to read the document later or any other parts of the installation.
In later versions of Windows (after Windows 7), PDF reader is automatically integrated into Internet Explorer or Edge. The error should not occur.