|If the XP is MCE you have to turn off a default setting in the Media Center settings. It's Call Display feature is on all the time Windows is running even when you aren't using Media Center, and that interferes with other software's ability to pick up the phone when a call comes into the modem. |
(Been there, with HotFax, done that, after finding an obscure mention of that problem on the Smith Micro web site).
The same may apply to all versions of Vista and Windows 7 that have Media Center - Premium, Ultimate, etc.
If the modems have two ports, they may not work correctly if the cable to the wall connection is in the Phone port rather than the Line port
If the computer(s) are using a DSL or ADSL high speed internet connection, or if the phone line the dial up modems connect to otherwise has DSL or ADSL capabilty enabled, you must use a DSL or ADSL filter inline between the wall jack and the dial-up modems, otherwise they can't work properly.
If the dial-up modems are working correctly and the proper software for them have been installed correctly, when you go to Control Panel - Phone and Modem - highlight and click on the modem's name - Advanced - Diagnostics - Query Modem, you should get a list of responses.
If that doesn't help, consult the Symantec help in the program or online.