My computer with Windows 7 64-bit does not recognize the Epson GT-S50. I've switched USB ports, reinstalled the software several times, and tried to install it on a second computer, but nothing changes.
I would suggest you first uninstall completely any old traces of Epson WorkForce Pro GT-S50 Document Scanner software/driver installed on your computer.
Visit the manufacturer’s website and check for the availability of uninstaller to remove all the traces of existing drivers from your computer.
After uninstalling the existing drivers, restart the computer and run the Microsoft Automated troubleshooting services to automatically diagnose and repair printer related errors.