hmm læs lige denne
http://support.euro.dell.com/dk/da/filelib/download/index.asp?fileid=R35443&sid=INS_PNT_P3CG_8000&st=læs setup.htm
Installing the drivers in Windows XP
NOTE: If you ordered your Dell computer with the Actiontec V.90 Internal Fax Modem already installed and configured no additional setup steps are necessary. This information is provided in case you need to reinstall the drivers for your modem, if, for instance, you change operating systems. In that case the drivers can be found on the Dell Software CD that came with your system.
Windows will detect the modem and install generic, "native" drivers that come with Windows XP. Click the Start Button in the lower left hand corner of the desktop and choose Control Panel.
Click to Classic View then choose Phone and Modem Options. Click the Modems Tab to bring it to the front and highlight the Lucent Win Modem and click Properties.
Click the Driver tab to bring it to the front, then click Update Driver.
The Hardware Update Wizard will start. Click "Install from a list or specific location" then click Next.
Click "Don't search, I will choose the driver to install" and click Next.
Click Have Disk and select the path or media type where the drivers are located, then click Next.
LTCBUS.INF will be located, click Open and then click OK.
Highlight Lucent Win Modem and click Next.
Click Finish to complete the installation.
Click to close the Modem Properties and Control Panel dialog boxes.