> 3.1.1 | Default Installation

> Take care that the modem setup file usbmodem.inf delivered with the module is at hand. Connect the USB cable to the module’s host application (for example the evaluation board DSB75) and the PC (if need be via hub). Windows detects the module as a new USB modem and opens the Found New Hardware (Wizard) box. Follow the instructions on the screen to locate and install the driver software and specify the path to the modem setup file usbmodem.inf. The modem setup file includes the Windows specific standard USB driver usbser.sys. The USB driver supports a virtual COM port emulation via USB and implements a USB modem based on the communication device class CDC ACM v1.1 (see [4]).
> Notes for Windows 2000 only:

> • | During the installation procedure you will be prompted for the usbser.sys driver. Make sure the file is present before you start the above inf file. The usbser.sys file is not delivered as a single file, but must be extracted from a Windows 2000 cabinet file. This is either the file driver.cab located in the I386 folder of the original Window 2000 CD or a later cabinet file inside the Service Pack. SP4 for example includes the sp4.cab file that can be found in its I386 folder. The usbser.sys driver from the Service Pack has priority over one provided with the standard Windows 2000 install CD.

> • | It is necessary to restart Windows 2000 to make the changes take effect.

> Windows installs and configures the modem by assigning an available (virtual) COM port to the physical USB port. If you are already using more than one COM port then the next available port will be allocated. Click Finish resp. Close to complete the installation. The following screenshots show important installation steps for an installation under Windows XP/2000 and Vista.
> After installation the “Siemens AG WM USB Modem” is listed under Control Panel | Phone and Modem Options | Modems
> Figure 1: Phone and Modem Options
> Installation Issues

> • | If Windows fails to assign the next free COM port to the USB modem and e.g., allocates a COM port already used by another modem you can manually select a free port as follows:

> Open the Windows Device Manager, select the installed “Siemens AG WM USB Modem”, click Properties, select the Advanced tab and click Advanced Port settings. From the listbox COM Port Number choose a free port. To make the changes take effect disconnect and re-connect the USB cable. If not yet successful, also restart Windows.
> Figure 2: Advanced COM port settings

> • | Under Windows XP/2000 a message may appear that the modem software has not passed Windows Logo testing. In this case it is possible to click "Continue Anyway" to proceed with the installation. Alternatively, the installation may be stopped in order to select Ignore as Driver Signing Option under Control Panel | System | Hardware | Driver Signing and to restart the installation.

> Figure 3: USB modem software verification under Windows XP/2000

> • | Under Windows Vista a window may pop up showing the message: "Windows can’t verify the publisher of this software". To continue with the installation select "Install this driver software anyway".

> Figure 4: USB modem software verification under Windows Vista

> • | After installation the input echo may be disabled, i.e. a terminal program might not display the entered AT commands. To enable the input echo, please enter the AT command ATE1.