Programs Using Old Winsock.dll File May Not Work in Windows


After you upgrade to a Windows version listed in the Applies To banner and you install or try to use a Winsock program, the program may not run, or you may receive the following error message when you try to run the program:

The following system files have been replaced with older versions by a program you recently ran. These files are currently in use and cannot be automatically repaired. Windows may not run properly until you exit and restart Windows so that these files can be automatically repaired.



When you install Dial-Up Networking, TCP/IP, or the IPX/SPX-compatible protocol in Windows, Setup renames the existing Winsock.dll file to Winsock.old and installs a new suite of Windows Sockets 1.1 interface files.

Current Winsock programs may not be compatible with the Windows Winsock.dll file due to proprietary services in the program's version of the file.

If the program you try to run is not compatible with the installed version of the Winsock.dll file, you may receive an error message or the program may not run.


To resolve this issue, use any one of the following methods:

  • Connect to your Internet service provider using Dial-Up Networking. Dial-Up Networking provides support for 16-bit and 32-bit Windows Sockets programs.

    For additional information about using Dial-Up Networking, view the "Connecting to a network by using Dial-Up Networking" topic in Windows 95 Help or see the following article in the Microsoft Knowledge Base:
    ARTICLE-ID: 138789
    TITLE : How to Connect to the Internet in Windows 95
  • You may be able to use both your current Winsock program and the Windows Winsock programs by following these steps:

    1. Copy the Winsock.old file from the Windows folder or the Windows\System folder to the folder containing the program's executable file.
    2. Rename the Winsock.old file in its new folder to Winsock.dll.

  • Contact the manufacturer of the Winsock program to inquire about a possible update.

More Information

The following Winsock programs may work if you place their version of the Winsock.dll file in the program's folder:

  • Chameleon
  • CompuServe Internet Dialer or CompuServe Net Launcher
  • FTP Software
  • Internet In a Box
  • Internet Office
  • Mosaic In a Box
  • NetCom Net Cruiser
  • Pipeline
  • Spry Air Series
  • Trumpet