Running 32 bit DLL on 64 bit Machine on Visual Studio

Solution:
1. Right click the Solution>Configuration Manager

2. In the Active solution platform, Choose <New>, under Copy Settings from, choose x86, click ok.
(ALL projects need to be compile under X86)

3. Make sure Build for all projects are checked.

P/S: If you have the problem on Visual Studio 2010 during compilation: Could not load file or assembly … or one of its dependencies. An attempt was made to load a program with an incorrect format (.resx file), use the following method to solve it.

1. Close all instances of Visual Studio.

2. From the Visual Studio Tools subfolder, open an elevated “Visual Studio Command Prompt (2010)” (using “Run as administrator” option). Change directory to "<system_drive>:\Program Files (x86)\Microsoft SDKs\Windows\v<x.xx>\bin\”.

3. Issue the command :

corflags /32bit+ ResGen.exe /force

4. Open <project_name>.csproj in notepad.

5. Add the following property <ResGenToolArchitecture>Managed32Bit</ResGenToolArchitecture> under the PropertyGroup section. Save and close the csproj file.

From: http://support.microsoft.com/kb/2028833