We are developing a device with USBTMC to be compatible with LabView. Is it possible for a user that has a PC without LabView installed to use our product if we supply them with an .exe application file? I know that the NI documentation states that the NI-VISA must be installed, if a .exe is properly prepared, will it install the NI-VISA or a suitable environment for the USBTMC device to work?
You would need to install LabVIEW Runtime Engine and NI-VISA on the deployment machine. The LabVIEW executable will not include these components. I would suggest that you create an Installer using LabVIEW Application Builder that will package all these components together. You can refer to the LabVIEW help for more information on creating custom installer.