USB dialup modem problems in Windows 10
Dial-up Quick Configuration Info
Dial-up error 633
This error appeared with the US Robotics USR5637 USB dialup modem when Windows 10 was updated to the Creator version (1703), and may also have appeared with other USB modems and devices. The error occurs when you try to use the modem, and the error code indicates that the modem is already "in use", even though it would seem not to be in use.
Before attempting to fix the problem, ensure that all doftware is up to date:
- In Windows 10 Settings, go to Update & Security and click on the "Check for updates" button
- Download the most recent update for USR5637 dialup modem from USRobotics Support: USR5637 56K* USB Controller Faxmodem with Voice
- Uninstall the existing US Robotics driver
- Install the driver from the downloaded update package.
This may fix the problem, particularly if Windows 10 or the driver has been updated with a solution to the problem.
If the problem is not fixed, the next step is a change to the Windows 10 Registry. Changes to the Registry can be quite risky - a mistake can make the computer unusable. Registry changes should be carefully made by a technically knowledgeable person.
The required registry change is described at Dial-up error 633 w/build 15063 (1703 Creators) Pro. The change is made by adding one extra line (SeLoadDriverPrivilege) to the registry value HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\RequiredPrivileges without changing any of the previously existing lines. Restart the computer after making the change,
The change is illustrated below