When you are trying to install Web Suite/ArchiOffice/EngineerOffice on
- Microsoft SBS 2008
- Microsoft SBS 2011
- Microsoft Windows 2008, 64 bit edition
you may come across the following possible 503 error messages:
Event log error message: The Module DLL C:\Windows\system32\RpcProxy\RpcProxy.dll failed to load. The data is the error.
The Module DLL 'C:\Program Files\Microsoft\Exchange Server\ClientAccess\Owa\auth\exppw.dll' could not be loaded due to a configuration problem. The current configuration only supports loading images built for an x86 processor architecture. The data field contains the error number.
On Microsoft SBS 2008, SBS 2011 and other 64-bit editions of Windows 2008, additional steps are to be taken after installation of Web Suite website in IIS 7.0. These steps ensure that Web Suite can run on the 64-bit system with other applications. In addition, there may be some configuration changes involved to make Web Suite compatible with Small Business Server (64-bit version). You may want your IT/System Administrator to handle it for you.
Warnings: Back up IIS files before making changes. You can do so by using the elevated command prompt and typing the following command:
%windir%\system32\inetsrv\AppCmd add backup "nameofyourbackup"
Note:
- You must include the quotes " " in your command.
- Some lines below are wrapped for readability.
- If you edit the lines referring to the "exppw" module, you MUST change both lines. If you do not, browsing to any page will fail with HTTP error 500.
- If you install service packs for Microsoft software (particularly Exchange/Outlook Web Access), re-check the entries in applicationhost.config. Service packs can overwrite changes to this file.
- Depending on the software or Windows components installed, some of the below items may not apply.
1. Run the following command with elevated privileges:
%windir%\system32\inetsrv\appcmd.exe set config -section:system.webServer/httpCompression /-[name='xpress']
This command disables a compression module which is enabled by default on SBS 2011.
2. Open a text editor or XML editor with elevated privileges (for instance, from the Start menu, right-click Notepad and select Run as Administrator).
3. In the file %windir%\system32\inetsrv\config\applicationhost.config,
Change the line based on the error message that you see on the screen or event viewer - application
Note that the "image" part of the entries will depend on your local installation and you should not change it.
If Outlook Web Access is installed on the server, perform the following additional steps. Note that the "path" part of the entries will depend on your local installation and you should not change it. Not all of these entries are present in every installation. You can ignore any entries that are not present.
4. In the file %windir%\system32\inetsrv\config\applicationhost.config, 
If you do not want to require HTTPS (SSL), you may use the IIS Manager to disable this requirement for specific virtual websites or directories. You may need to recycle application pools and/or restart IIS in order to apply these changes.