Knowledge Base

Unblocking Syncing Master (server module) in the system firewall for Windows XP Service Pack 2

This article is meant for users of CodeTwo Public Folders. This software has been discontinued. You can check the list of currently available CodeTwo products here.


Service Pack 2 for Windows XP introduces a firewall, which blocks access to a computer from other computers in the network.


The installation program of CodeTwo Public Folders automatically unblocks the Syncing Master in the Windows XP firewall. If there are communication problems between the Outlook Add-ins and the Syncing Master, follow the procedure below to make sure the Syncing Master is not blocked by the firewall.

The steps below should be performed on the computer with the Syncing Master (server module) installed.

  1. First run the configuration program of the system firewall. To do this click Start and select Settings,Control panel, Windows Firewall. The Windows firewall dialog (fig.1) will be displayed.

    Fig. 1. Configuring the firewall of Windows XP. Make sure the "Don't allow exceptions" option is not checked.

  2. If Off is selected, the firewall is deactivated and the CodeTwo Public Folders software is not blocked. Skip further procedures.
  3. If the On option is selected, the firewall is active. Make sure the option Don't all exceptions is not checked.
  4. Go to the Exceptions tab and check if the list includes the C2PublicFoldersServer.exe program (fig.2). If the program is on the list, you should check if it is unblocked for a proper range of computers, for details read further below. If the program is not on the list, it should be added to the list.
  5. In order to add the CodeTwo Public Folders Syncing Master to the list, click the Add Program button (fig.2) in the Exceptions tab. Then click the Browse button and indicate the location of the C2PublicFoldersServer.exe file. Usually it's in the folder: "C:\Program Files\CodeTwo\CodeTwo PublicFolders Server".
  6. Confirm and close all dialog windows to save the entered modifications.

    Fig. 2. List of the unblocked programs in the firewall.

  7. If you want to restrict access for certain computers to the CodeTwo Public Folders Syncing Master (for example from the Internet), select it on the Programs and Services list, click the Edit button and then the Change scope button. Select one of the three options, depending on the range of computers which you would like  to have access to the program (fig.3).

    Fig. 3. Changing the range of computers with access to the CodeTwo Public Folders Syncing Master.

  8. If you choose the Custom list option, make sure that the IP addresses of all computers with CodeTwo Public Folders Outlook Add-in installed are among the defined computers.

    For example:
    If a computer with an Outlook Add-in installed has the IP address:, you should enter IP or a subnetwork in the Custom list field the in following way: In this case the subnetwork mask determines that all computers with an IP address beginning with 192.168.100 will have access to the program.