Are you using the built application on a different machine?
If so, you will need to install NI-VISA on the machine you are trying to use VISA.
Also, you probably want to right click on the control and "allow undefined names" so you can type in the visa resource names like "ASRL1::INSTR".
If you want to port over the aliases "COM1, COM2", etc then you can copy your visaconf.ini file (on a Windows 95 system: vxipnp >> win95 >> NIvisa >> visaconf.ini) into the same directory as your executable.