Corflags is the inbuilt tool of Visual Studio which can be used to find out the type of .dll i.e 32 bit, 64 bit or any CPU in .Net application . This tool is available in Visual studio 2005 onward. i.e. VS 2005/2008/2010/2013
These are the following steps to check in Visual Studio
Step 1: Go to visual Studio command prompt like this
Step 2: Make Sure that Corflags is working in your system
Type the Corflags in Command Prompt like this
Note: if this syntax is not working then there is some problem in Environment Variable of the System
You can fix this issue like this post
http://helpdeskgeek.com/how-to/fix-not-recognized-as-an-internal-or-external-command/
Step 3: Go to the file Location of DLL and type the syntax like this in below image
Corflags AjaxToolKit.dll
This is the short summary to determine the type of dll
Any CPU: PE = PE32 and 32BIT = 0
x86 bit: PE = PE32 and 32BIT = 1
64-bit: PE = PE32+ and 32BIT = 0
Summary
This tool will be handy if we have to run the application on 32 and 64 bit machine. If some dll which is only supporting X86 i.e 32 bit then we cannot run that application on 64 bit machine. On this scenario, we can use this tool to find out which dll is creating problem. I hope it will help to somebody.