JSI Tip 8363. When you attempt to install a modem in Windows XP SP2, you receive 'Windows was unable to install the modem'?

When you attempt to install a serial, or USB, modem on Windows XP SP2, you receive:

Windows was unable to install the modem.

This problem will occur if there are no Value Names under the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Modem key. This condition is likely the result of removing 3rd-party modem software.

To resolve this issue:

1. Copy / Paste the following into Notepad:


"Group"="Extended base"


2. Save the file as Modem.txt.

3. Rename the Modem.txt file to Modem.reg.

4. Right-click the Modem.reg file and press Merge, or open a CMD.EXE window and type regedit /s Modem.reg.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.