Clicking on the blue “e” in taskbar does not launch a new process in IE8

Hi everyone!

This is Shahinur continuing our discussion on IE8 changes related to its Loosely Coupled IE design.

In previous versions of the browser, when you start a new instance of Internet Explorer (by clicking on the blue e in taskbar, for example) you will notice that a new iexplore.exe process starts. If you are a user who does this often, you could run up your process count pretty easily, especially now that you have separate frame process and a tab process in IE8.

In order to solve this problem and save system resources, IE8 has a feature called “Merged Frame Process” or MFP. When a frame process starts, MFP makes an intelligent decision as to whether it can and should merge into an already running frame process. The decision involves maintaining the separation of session context (eg, session cookies) between sessions among other things. In addition, various conditions (such as running with “no add-ons”, “ie7emulate”, “admin”, “private browsing mode”, being the same user) must match between two frame processes in order for them to merge.

Once the merge decision has been made, the new frame process will communicate to the existing one and then exit. In this way, we minimize the number of IE frame processes IE8 uses for the logged on user. This is a large performance improvement for users that “click the blue e” instead of creating new tabs.

Be careful not to confuse the frame process with the tab process. Let’s say you keep launching IE from your taskbar while all other conditions remain the same, you will end up with only one Frame process but possibly several Tab Processes. The number of tab processes will be based on the Tab Process Growth algorithm I explained in my earlier blog.

If you do not want frames to merge, you do have option to control it both with a regkey and with iexplore.exe command line switches.

Command Line switches:

“-FrameMerging” – regardless of the user’s default, this iexplore.exe frame process will merge with another compatible frame process.

“-NoFrameMerging” – regardless of the user’s default, this iexplore.exe frame process will not merge with any other frame process.

Registry key details:

HKCU\Software\Microsoft\Internet Explorer\Main\FrameMerging

0 – disable frame merging

1 – enable frame merging (default)


The IE team

Comments (9)
  1. David says:


    I tried the regkey and it works when I run IE8 from anywhere except from an email.

    In my case, users get emails  (outlook) with a link within the message body and when it's clicked IE8 opens in frame merging mode regardless of the regkey entry

    did you knkow that?

    how can I solve it?

    it's important because my users are working on my web app and when one of these emails arrive and click on the link IE must open with a diferent session.

    Thanks in advance


  2. Anonymous says:

    Hello David,

      By default IE7 and IE8 open links in new tabs. You should go to the setting: Tools->Internet Options->Tabs->Settings->"Open links from other programs in". For this setting, please choose "New Window".

  3. Sounak says:


    The recommended setting doesn't work in IE9, Frames are still being merged when trying to open a link from mail. Is there a way so as to ensure that links from other instances are opened in a new Frame process to avoid session sharing ?

    FrameMerging and SessionMerging are already set to 0 in HKLM and HKCU.



  4. AxelRMSFT says:

    At Sounak – We are investigating and will follow up with you on your comment!

    Thanks for your feedback!

    The ASKIE Support Team

  5. Mike G says:

    @AxelRMSFT:  was there a follow-up on your research?  We're encountering the same issue.



  6. AxelRMSFT says:

    Here are a few steps to try after you have added the SoftwareMicrosoftInternet ExplorerMainFrameMerging  key and set it to 0

    Make sure all IExplore process are closed (use task manager to confirm)

    Clear your Cache. You can use the Ctrl-Shift+Del key to bring up the Browser History Dialog

    Delete history

    Logout and log back in and test again.

    you may also have to consider…/session-cookies-sessionstorage-and-ie8.aspx

    HKCUSoftwareMicrosoftInternet ExplorerMain – SessionMerging(dword)

    0 – turn off isolation session merging

    1 – enable isolation session  merging

    Both Registry keys Reg file:

    Windows Registry Editor Version 5.00

    [HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerMain]



  7. Mike M says:

    It appears that the registry setting ("FrameMerging") only works on IE 10, and not IE 8.

    I have not verified this yet, but that is the advice I got from the development staff at my company.



  8. Amit Sinha says:


    I also tried the above options. The solution does not work for IE8. After making the registry changes and IE settings, though the new instances gets launched in newer window, but look likes behind the scene from session variables and cookies perspective, fames are still same and cause application malfunctioning. Any more inputs on this issue for IE8 browser.

  9. Amit S says:

    It seems like that. Solutions suggested to disable the frame merging does not work in IE8. I implemented both the changes – Registry changes and IE settings. Though the new application instance gets launched in different tab, but cookies data and sessions data for both the frames get corrupted or merged causing malfunctioning of application behavior. Despite the changes from technical perspective two sessions in different window , looks like still tagged to same Frame or Process ID.

    Any more inputs or solution to fix the completely disable the Frame merging in IE8?

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