You had me at "Hello World" : com interop

ActiveX component can't create object, when creating a 32-COM object in a 64-bit machine

HelloWorld — Wed, 12 Dec 2007 10:26:00 GMT

I had two posts to resolve an issue with applications that use a 32-bit COM object in a 64-bit OS. Workaround for executable, and ASP.Net.

I recently helped someone who had the same problem, but with a VB Script application, executed with cscript.exe. This VB script application uses a 32-bit COM object and failed to run on a 64-bit OS. The error, Microsoft VBScript runtime error: ActiveX component can't create object: 'XXXXXX'.

To fix the issue, the script must be executed with the right executable. There are two cscript.exe in the 64-bit OSes. One is located at %WINDOWS%\System32, and the second one is located at %WINDOWS%\SysWOW64.

The one under System32, is a 64-bit version. The one under SysWOW64 is the 32-bit version. Run the VBS application using the 32-bit application.

Why System32 contains 64-bit binaries, and SysWOW64 contains 32-bit is another story, but there is a very good reason behind it, backward compatibility. :)

Using X86 COM interop with ASP.Net application in Windows x64

HelloWorld — Sat, 14 Jul 2007 05:51:00 GMT

It has been almost two months since my last post. It has been very busy here..

I got several good notes with one my previous post, about using x86 COM interop in x64 environment. I also had few questions about using x86 COM interop with ASP.Net application in the 64-bit Windows, such as Windows Server 2003 x64, or Vista x64.

Well, IIS in 64-bit Windows is also 64-bit and uses 64-bit version of .Net Framework. You might deployed your app as pre-compiled binaries or deploying the source, either way, the same error will be thrown in the app is using a 32-bit COM interop. The same error, Retrieving the COM class factory for component with CLSID {GUID HERE} failed due to the following error: 80040154.

If you deployed the ASP.Net source code to the server, ASP.Net does the compilation and it is more challenging to force ASP.Net to compile it as 32-bit application, as the IIS itself is 64-bit.

There is a way to do it, I don't say that this is ideal, but it works.

Configure IIS to run 32-bit ASP.Net application.
http://technet2.microsoft.com/WindowsServer/en/library/140077b8-8c96-49b0-be17-e47095983c2b1033.mspx?mfr=true
Register ASP.Net 32-bit with IIS.
Open a command-prompt window at %windows%\Microsoft.Net\Framework\v2.0.50727 and call aspnet_regiis -i.
Enable the 32-bit ASP.Net web service extension from IIS Service Manager (it is not automatically enabled from step 2).

Your ASP.Net application and your 32-bit COM interop now will work. The most ideal situation would be to get the 64-bit version of the COM interop.

x86 COM Interop in x64 Environment.

HelloWorld — Thu, 12 Apr 2007 20:44:00 GMT

I encountered a problem with one of my application. It stops working when I executed it on Windows 2003 Server 64-bit. It threw an exception:

Retrieving the COM class factory for component with CLSID {GUID HERE} failed due to the following error: 80040154.

The COM interop is an x86 interop, and that causes the exception. To address this issue, I have to recompile the app and change the target platform from AnyCPU to x86. After that, it works great.