The Internet Explorer Manager process is always a 64-bit process in 64-bit versions of Windows 8 or later operating systems. This is an architecture change in Internet Explorer 10. By default, tab processes can be either 32-bit or 64-bit processes, except when the TabProcGrowth registry entry is set to 0. When this registry entry is set to 0, the tabs run in the same process as the manager process, which in this case is 64-bit. However, some browser add-ons do not have a 64-bit version. Therefore, they do not work as expected.