i found this one their site, its not dor xp but it may help
NOTE: This assumes that the modem is jumpered for a plug & play configuration, which is the default factory setting.
1. Determine whether Windows in improperly configuring the modem. To ensure and correct for this, do the following:
A. Open the Device Manager, click Start/Settings/Control Panel/System/Device Manager.
B. Remove any Supra modems found under 'Modems' and/or 'Other Devices'.
C. Reboot the system
When the system reboots, Windows should find the modem and load the appropriate drivers. Insert the driver disk if requested. In most cases, this should correct the situation.
2. If the modem is not found when the system reboots or there was nothing listed in the Device Manager, it will be necessary to check the system registry. To do this, do the following:
Note: It is recommended that you make a backup of your Registry before proceeding.
A. Click Start/Run.
B. Enter REGEDIT and click OK.
C. In the Registry Editory, locate the following registry key:
HKEY_LOCAL_MACHINE\Enum\ISAPNP
D. Click the "+" in front of this key to expose any sublistings.
E. On the left window below the above key, there should be a listing for a "SUP####" (without the quotes). Its presence would indicate that Windows has detected the modem in the system.
F. Right-click on the SUP#### key and select Delete.
G. Confirm the removal and close all windows.
H. Restart the computer.
Windows should then detect the modem on reboot. If the modem is still not detected or there was no listing of an SUP#### in the registry, you should try reseating the modem into another slot in the computer.
also check this
http://www.diamondmm.com/default.asp?menu=support&submenu=winXP_stuff&item=modems
