Share via

Referencing Usbser.sys for USB Modems

Modem devices that use the Universal Serial Bus (USB) might use the Microsoft Usbser.sys driver.

Referencing Usbser.sys requires adding or modifying the DDInstall, DDInstall.Services, and DDInstall.HW sections of your modem INF file. These sections must use the include directive to include sections from the Mdmcpq.inf INF file as follows.


include=mdmcpq.inf AddService=usbser, 0x00000000, LowerFilter_Service_Inst 


The following sections appear in the Mdmcpq.inf file in Windows Vista, Windows Server 2003, Windows XP, and Windows 2000:

  • FakeModemCopyFileSection

  • LowerFilter_Service_Inst

  • LowerFilterAddReg



Send comments about this topic to Microsoft