How to check 32bit or 64bit Internet Explorer 10 and 11?

Question

Before IE10 (likes IE9), I can use window.navigator.platform to check IE is 32bit or 64bit.

But for IE10 (IE11), window.navigator.platform always returns 32bit.
When I open IE11 from C:\Program Files (x86)\Internet Explorer, I saw there is a process IExplorer and another process IExplorer*32.

If one more tab is opened, another process IExplorer*32 is created.
But it's the same thing when I open IE10 (IE11) from C:\Program Files\Internet Explorer.

So, I don't know whether IE10 and IE11 has both 32bit and 64bit. Maybe the parent framework is 64bit, and each tab is 32bit.
Anyone know this?

Solution

FYI: By default, IE10+'s frame/manager process runs at 64bit, while Desktop Tab processes run in 32bit.

Comments

[abarisone]

Could you please elaborate more your answer adding a little more description about the solution you provide?

[GlennFromIowa]

Very helpful. Based on the How do I tell whether my IE is 64-bit? (For that matter, Java too?) question, I first found the iexplore.exe entry in Task Manager. I would not have known to look for the child entries if not for this answer!