Running Internet Explorer 32-bit or 64bit for IE Toolbar Developers

Which one should I run? 

As of  Internet Explorer (IE) 10+, Microsoft has change the way IE Managed Process is run.

If you are using a Windows 64-bit version,  IE will always run as a 64-bit process.

To check if you run what Windows architecture you are running

Start->Run-> Type CMD and cut and paste the following

wmic os get osarchitecture














So if you manually launch Internet Explorer from this 32-bit folder, 

C:\Program Files(x86)\Internet Explorer\iexplore.exe

on Windows 64-bit version, it will run the 64-bit version located here

C:\Program Files\Internet Explorer\iexplore.exe


Tip-of-the-hat to this excellent article by Eric Law at IEInternals blog:

http://blogs.msdn.com/b/ieinternals/archive/2012/03/23/understanding-ie10-enhanced-protected-mode-network-security-addons-cookies-metro-desktop.aspx