I have created an c++ com dll which uses LoadLibrary to load cdintf400.dll. I am currently testing this on a 64 bit machine under both IE7 32 bit and IE7 64 bit. I have compiled two dlls. One compiled as x86 for the 32 bit version of IE and one as x64 for the 64 bit version of IE. The 32 bit version works fine but when I run the 64 bit version I get error code 193 when calling LoadLibrary. This error code suggests your dll is not a valid win32 application. Do you have any idea why this does not work or do you have a work around?