JSI Tip 2441. Control Panel / Modems doesn't start in Windows NT 4.0?

When you try to start Control Panel / Modems or Control Panel / Telephony.. / Unimodem.. / Configure, the hourglass flashes briefly but the dialogue box does not open.

If you try to open modem properties from a CMD prompt, it doesn't open:

control modem.cpl
rundll32.exe shell32.dll,Control_RunDLL modem.cpl

NOTE: The rundll32.exe commands are case sensitive.

Possible causes of this difficulty are:

1. Modem.cpl is missing or damaged. Expand it from the CD-ROM:

    expand i386modem.cp_ %SystemRoot%System32Modem.cpl

2. The %SystemRoot%System32Modem.cpl file doesn't have proper permission. Set the following permissions:

    Administrator - Full Control
    Everyone - Read
    Server Operators - Change
    SYSTEM - Full Control

3. A registry key/value is missing or damaged. Use Regedt32 to verify / fix:

    HKEY_LOCAL_MACHINESystemCurrentControlSetControlClass\{4D36E96D-E325-11CE-BFC1-08002BE10318}

  Value Name: Installer32  Data Type: REG_SZ  String: Modem.Cpl,ClassInstall32  Value Name: Icon  Data Type: REG_SZ  String: 0   Value Name: Default Service  Data Type: REG_SZ  String: Modem   Value Name: Class  Data Type: REG_SZ  String: Modem   Value Name:   Data Type: REG_SZ  String: Modem