Name: US Robotics USR5639 Driver
Author: US Robotics

Question 1

Install fails or rolls back?

Accepted Answer

Run the USR5639 installer as administrator and try Windows 7 compatibility mode. If Windows blocks the older driver, install manually via Device Manager: right-click the modem/unknown device, Update driver, Browse, and point to the extracted USR5639 INF file.

Question 2

Modem not detected?

Accepted Answer

Use a rear USB 2.0 port directly on the PC, not a hub. In Device Manager, scan for hardware changes and check under Modems or Ports (COM & LPT). Reconnect the USB cable after the driver is installed.

Question 3

Driver/version conflict?

Accepted Answer

Uninstall existing USR5639 or generic modem entries and the driver package, reboot, then reinstall the USR5639 driver. In Device Manager, manually select the US Robotics driver to stop Windows Update replacing it with a generic modem driver.