How to Remove COM Internet Services (CIS) and RPC over HTTP Proxy Support

This article describes how to disable or remove Component Object Model (COM) Internet Services (CIS) (Windows NT 4.0 or Windows 2000) and RPC over HTTP Proxy (Windows Server 2003) support.

RPC over HTTP version 1 (Windows NT 4.0, Windows 2000) and version 2 (Windows Server 2003) introduce support for a new remote procedure call (RPC) transport protocol that allows RPC to operate over Transmission Control Protocol (TCP) port 80. Version 2 also allows RPC to operate over TCP port 443. Operating over TCP ports 80 and 443 allows a client and a server to communicate in the presence of most proxy servers and firewalls. COM Internet Services allows DCOM to use RPC over HTTP (referred to as the Tunneling TCP/IP Protocol in the DCOM Configuration utility [Dcomcnfg.exe]) to communicate between DCOM clients and DCOM servers.

For additional information about COM Internet Services and RPC over HTTP, see the "References" section later in this article.

RPC over HTTP requires the use of a specially configured server that is running Internet Information Services (IIS) to allow RPC to operate over the HTTP protocol between an RPC client and that server. The following procedures describe how to disable or remove COM Internet Services from Windows NT 4.0 and Windows 2000 and how to disable or remove RPC over HTTP Proxy support from Windows Server 2003.

Note On computers that are running Windows Server 2003, RPC over HTTP is required for Microsoft Exchange Server 2003 and for Microsoft Office System if Microsoft Office Outlook 2003 has been configured to use RPC over HTTP for checking corporate e-mail. Disabling or removing RPC over HTTP will prevent Office Outlook 2003 clients from connecting to their mailboxes by using RPC over HTTP. If you require RPC over HTTP functionality in your environment, you may want to disable DCOM instead of RPC over HTTP. For additional information about how to disable DCOM, click the following article number to view the article in the Microsoft Knowledge Base:

Determine Whether COM Internet Services or RPC over HTTP Proxy Is Installed

Windows NT 4.0

On servers that are running Windows NT 4.0 with the Windows NT Option Pack installed, the easiest way to determine whether COM Internet Services is installed is to perform a search on all partitions for Rpcproxy.dll. The MSDN "COM Internet Services" article that is included in the "References" section of this article instructs the administrator to copy Rpcproxy.dll to the C:\Inetpub\Rpc folder from the default folder, C:\Winnt\System32. If you find Rpcproxy.dll on the server, COM Internet Services is installed.

Another method to determine whether COM Internet Services is installed and enabled is to look for the Tunneling TCP/IP Protocol in DCOM Configuration. To do this, run Dcomcnfg.exe, and then click the Default Protocols tab. If the Tunneling TCP/IP Protocol is listed, support for COM Internet Services is installed and enabled.

Windows 2000 and Windows Server 2003

To determine whether COM Internet Services Proxy or RPC over HTTP Proxy is installed and enabled, follow these steps:

1. In Control Panel, click Add or Remove Programs, and then click Add/Remove Windows Components.
   
   The Windows Components Wizard starts.
2. Click Networking Services, and then click the Details button.
   
   If COM Internet Services Proxy (Windows 2000) or RPC over HTTP Proxy (Windows Server 2003) is checked, COM Internet Services Proxy or RPC over HTTP Proxy support is installed and enabled on the server.

Note To remotely or programmatically determine whether COM Internet Services Proxy or RPC over HTTP Proxy is installed, you can search for Rpcproxy.dll on Windows 2000 and Windows Server 2003 installations.

Another method to determine whether RPC over HTTP support is installed and enabled is to look for the Tunneling TCP/IP Protocol in DCOM Configuration. To do this, follow these steps:

1. Run Dcomcnfg.exe.
2. If you are using Windows Server 2003, follow these additional steps:
   1. Under Console Root, click Component Services.
   2. For the local computer, right-click My Computer, and then click Properties.
3. Click the Default Protocols tab.
   
   If the Tunneling TCP/IP Protocol is listed, support for RPC over HTTP support is enabled.

Remove COM Internet Services or RPC over HTTP

Remove COM Internet Services in Windows NT 4.0

1. Remove the RPC virtual directory in Internet Service Manager for IIS:
   1. On the Start menu, point to Programs, point to Windows NT 4.0 Option Pack, point to Microsoft Internet Information Server, and then click Internet Server Manager.
   2. In the console tree, click Console Root/IIS/ComputerName/Default Web Site.
   3. Expand Default Web Site, and then delete the RPC virtual directory.
2. Remove the RPC Proxy ISAPI filter in the Internet Service Manager for IIS:
   1. In the console tree, click Console Root/IIS/ComputerName, right-click ComputerName, click Properties, choose WWW Service in the Master Properties list box, and then click to select the Edit button.
   2. Click the ISAPI Filters tab, click the RpcProxy ISAPI filter, and then click the Remove button.
3. Remove Tunneling TCP/IP from the DCOM protocol list and disable COM Internet Services support in Dcomcnfg.exe:
   1. Run Dcomcnfg.exe.
   2. Click the Default Properties tab.
   3. Click to clear the Enable COM Internet Services on this Computer check box.
   4. Click the Default Protocols tab.
   5. If the Tunneling TCP/IP protocol is listed, click it, and then click the Remove button.
   6. Restart the server for the changes to take effect.

Remove COM Internet Services in Windows 2000 or Remove RPC over HTTP in Windows Server 2003

1. Disable COM Internet Services Proxy and RPC over HTTP Proxy:
   1. In Control Panel, click Add or Remove Programs, and then click Add/Remove Windows Components.
      
      The Windows Components Wizard starts.
   2. Click Networking Services, and then click the Details button.
   3. Click to clear COM Internet Services Proxy (for Windows 2000) or RPC over HTTP Proxy (for Windows Server 2003), and then click Next two times.
2. Remove Tunneling TCP/IP from the DCOM protocol list, and disable COM Internet Services:
   1. Run Dcomcnfg.exe.
   2. If you are using Windows Server 2003, follow these additional steps:
      1. Under Console Root, click Component Services.
      2. Double-click the Computers folder to open it.
      3. For a local computer, right-click My Computer, and then click Properties
         
         For a remote computer, right-click the Computers folder, click New, click Computer, type the computer name, right-click that computer name, and then click Properties,
   3. Click the Default Properties tab.
   4. Click to clear the Enable COM Internet Services on this Computer check box.
   5. Click the Default Protocols tab.
   6. If the Tunneling TCP/IP protocol is listed, click it, and then click the Remove button.
   7. Restart the server for the changes to take effect.

For additional information about RPC over HTTP support in Windows Server 2003, visit the following Microsoft Web site:For additional information about COM Internet Services, visit the following Microsoft Web site: