BizTalk360  heavily depends on the Microsoft.BizTalk.ExplorerOM DLL that comes with Microsoft BizTalk server. One of the restrictions of the component is that it does not support 64-bit.

IIS 7.0

IIS 7.0 is much more granular than IIS 6.0. Therefore, you can setup 32-bit mode at the application pool level rather than on server level allowing to run both 32-bit and 64-bit application on the same server.

Here's how you can do it from the IIS 7 Manager:

  1. Right click on the Application Pool and select "Advanced Settings…" or select the same from the Actions pane after selecting the Application pool
  2. Change the "Enable 32-bit Applications" to True (if you want the application pool to spawn in a 32-bit mode)
  3. Click OK to save the changes

The following blog article explains more in-detail -

IIS 6.0

On systems with IIS 6, the Enable32bitAppOnWin64 property is a global property that affects all websites and applications on an IIS server. Make sure you do not have any other 64-bit applications running on the same server or plan to run BizTalk360 in a different server and point to the environment remotely.

ASP.NET 2.0, 32-bit version

To run the 32-bit version of ASP.NET 2.0, follow these steps:

  1. Click Start > Run. Type cmd, and then click OK
  2. Type the following command to enable the 32-bit mode:
    cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1
  3. Type the following command to install the version of ASP.NET 2.0 (32-bit) and to install the script maps at the IIS root and under:
    %SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe -i
  4. Make sure that the status of ASP.NET version 2.0.50727 (32-bit) is set to Allowed in the Web service extension list in Internet Information Services Manager