You have probably noticed that the recent version of Microsoft Internet Explorer may launch several instances of itself displaying each opened web-page in a separate instance of the iexplore.exe process. This behavior is due to the fact that Internet Explorer 8 now implements a feature called Loosely Coupled IE (LCIE) that uses separate instances of theiexplore.exe process for IE frame window and tabs.
LCIE provides benefits such as enhance isolation of browsing session and reliability so that IE can restart or re-open an individual tab without losing all IE sessions when a problem occurs or IE crashes.
Yet, these enhancements bring additional difficulties when web testing in IE8. For example, a web test may have been recorded on a page in one instance of iexplore.exe and then when the web test is played back, it is launched in another instance of iexplore.exe.
We have published two technical papers that tell you how to avoid this and other IE8; issues:
There is yet another solution: you can now disable the Loosely Coupled IE feature. To disable LCIE:
- Open the registry editor.
- Go to the
HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerMain section and locate the
TabProcGrowth key. If the key does not exist, create a new DWORD (32-bit) Value or String Value and name it as
- Set the value of the
TabProcGrowth key to 0. This will instruct IE to open all of the tabs within the same iexplore.exe process.
By switching the LCIE off, you can force Internet Explorer 8 to behave just like Internet Explorer 7 which hosts all pages opened in a certain instance of a browser within a single iexplore.exe process. However all benefits of Loosely-Coupled IE will be disabled as well. Therefore we recommend that you turn the feature on once your web testing is done.