I have an application which uses WinHTTP, and it seems under Windows 7 (64-bit; have yet to test the 32-bit version) the call to WinHttpOpen fails, returning "The group or resource is not in the correct state to perform the requested operation." This corresponds to error code 5023, and occurs for the Administrator as well as a standard user. The C++ DLL containing this call was compiled using Visual Studio 2008 (32-bit) on a Windows XP Professional system. Other than Outlook 2007, this is an otherwise clean install in a VM. Thanks!