32-bit browser applications may not work as expected in Internet Explorer 10
The Internet Explorer 10 Manager process is always a 64-bit process in 64-bit versions of Windows 8. 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.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
To work around this issue, change the value of the TabProcGrowth registry entry to an integer number that is greater than 0. To do this, follow these steps:
Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.
In the search box, type regedit.
Tap or click the displayed Regedit icon. Locate and then select the following registry entry:
Change the value of the registry entry.
Note If you do not want to change the registry setting, you may have to run add-ons that are written for 64-bit browsers. Contact the software vendor to check whether a 64-bit version of the add-on is available.
for me, the registry key is HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main\TabProcGrowth