By default, Internet Explorer will run 32-bit processes for rendering pages, even on 64-bit OSes and even if you start the 64-bit desktop version of IE. There are several settings required to use 64-bit browser processes.
Why is this the default?
The only reason for this is to preserve support for Browser add-ons that might only be built for 32-bit versions of IE. Below is what the Manage Add-ons screen (found under Tools->Manage Add-ons in IE 10 & 11) looks like. Notice the Architecture column. If you rely on any add-ons that only show “32-bit” on this screen and make the settings below to enable 64-bit Internet Explorer, those add-ons will stop working.
Internet Explorer 11 - Manage Add-ons
Why do we want to change it?
64-bit processes have access to more memory. Assemble models contain complex 3d data and larger models can benefit, and some extremely large models may require the additional memory to successfully load.
How do we change it?
Internet Explorer 10 & 11 require several configuration changes to enable their 64-bit versions.
General Settings - Enable the checkboxes surrounded by red rectangles. There is only one option that needs to be selected in Windows 7, while Windows 8 will require two.
Windows 7 - Internet Explorer 11
Windows 8 - Internet Explorer 11
Zone-Specific settings - After configuring these general settings, you may also need to check the “Enable Protected Mode” option for whichever zone Assemble is in. To determine which zone Assemble is in (this will be different from machine to machine), load Assemble in IE, right-click on an open area of the page and select properties. In the example below, Assemble is in the Local Intranet zone, so I need to verify that the Local Intranet zone settings have “Enable Protected Mode” checked.
Properties showing Assemble (developer environment) is in the Local Intranet Zone
Internet Explorer 11 - Zone Protected Mode
To verify that these changes are working as expected, close down all Internet Explorer Windows then open a single IE window. Navigate to assemble (important) and open Task Manager, then switch to the Details tab. Find the ‘iexplore.exe’ processes. Right-click each of them and select properties. In the Location field you should see “C:\Program Files\Internet Explorer”. If you see “C:\Program Files (x86)\Internet Explorer” then you’re still running in 32-bit mode. You need to check each iexplore.exe process, as sometimes one of the processes will be 32-bit while the others are 64-bit. You can also get a copy of “Process Explorer” from http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx and use that instead of Task Manager. After running it, click on “View” -> “Select Columns” -> “Process Image” tab and ensure that the “Image Type (64 vs 32-bit)” checkbox is checked.