IE 11 high CPU utilization, invisible instances, allocated memory growing RRS feed

  • Question

  • I got a new computer for a client, and almost immediately, he began complaining about performance. It turns out that the culprit is always close to 100% utilization by some combination of iexplore.exe. He does, after all, keep many news pages open all day every day. But there are more instances of iexplore.exe than he has copies of IE open. But if we close all open copies, it closes these phantom ones as well.

    None of that would be a problem were it not for the facts that 1) the CPU usage is so high and 2) the amount of RAM allocated to a single instance continues to grow over time. I saw one yesterday that was up to almost 1 GB.

    While a virus is a possibility, I find it unlikely on a new computer like this, so I want to check other things before I start throwing random AV checkers at it.

    This user is a tinkerer and can rarely tell me what has changed. He fiddled with his IE security settings (ActiveX), then thought he set it back, but could not then get to his bank's website. Setting IE security back to the default fixed this.

    So it is highly likely that he has been into the settings. And while I could just do a reset of IE settings, I first want to know if there are specific settings that can cause high CPU utilization and cause each process to continue to consume more RAM over time. I have heard that perhaps leaving script debugging enabled can do this, but I figure someone here on the forum may be able to help target the specific cause.

    Friday, May 20, 2016 3:06 PM

All replies

  • In order to diagnose your problem we need to run Windows performance toolkit the instructions for which can be found in this wiki

    If you have any questions feel free to ask

    Please run the trace when you are experiencing the problem

    Wanikiya and Dyami--Team Zigzag Windows IT-PRO (MS-MVP)

    Sunday, May 22, 2016 3:54 PM
  • I will try to do that; however, with this brand-new computer, I am pretty sure my client will not want me to take the time to download, configure, and run the trace tools. He thinks there is just something wrong with the computer, and his solution was simply to switch to Chrome (which he has already done). But that simply avoids the issue and leaves us with unexplained issues that may well pop up in other ways, given the degree to which Internet Explorer is integrated with the operating system.

    In the meantime, I am looking for two things:

    1. An explanation/examples of why there are more instances of iexplore.exe than there are instances of Internet Explorer open in the user interface, and
    2. Known issues that could cause instances of Internet Explorer to continue to grow in amount of memory allocated/consumed. I can see no reason why a dormant instance (i.e. on the task bar but not having the focus) should continue to grow like this.

    I have no doubt that this is somewhat related to the user's patterns of internet usage and web page content (he keeps many news sites open continuously); however, he uses many of the same pages on a Windows 7 computer at his home with no such growth in Internet Explorer memory usage. So it is still specific to this new computer that we just set up about three weeks ago. And he has little or no patience for diagnostics. But he is very prone to tinkering with settings. Sigh...

    Also note that I have already also checked all add-ons and Search Providers. There is only Bing as a search provider, and I see no Toolbars/Extensions besides the very common ones such as Flash & Office Document Cache Handler.

    Sunday, May 22, 2016 4:40 PM
  • Hi Brian D. Hart,


    I suggest that we may try Process Explorer to check which process caused high CPU.



    Best Regards,


    Please mark the reply as an answer if you find it is helpful.

    If you have feedback for TechNet Support, contact tnmff@microsoft.com

    Monday, May 23, 2016 1:00 PM
  • But we already know it is iexplore.exe (multiple instances) having high CPU. And this is apparently some sort of memory leak because, in addition to high CPU usage, the amount of memory allocated to each of several instances of iexplore.exe continues to grow.

    So my questions are very specific to iexplore.exe: 1) what causes the extra copies that are opened when one opens some websites and 2) why would the amount of memory used by a specific instance continue to grow over time?

    Monday, May 23, 2016 1:06 PM
  • Hi,

    We haven't heard from you in a couple of days, have you solved the problem? We are looking forward to your good news.

    Best Regards,


    Please mark the reply as an answer if you find it is helpful.

    If you have feedback for TechNet Support, contact tnmff@microsoft.com

    Monday, June 20, 2016 1:46 AM
  • I already know which processes are using high CPU utilization: multiple instances of iexplore.exe. So Process Explorer will just tell me that. The question is more specific:

    • Why are there more iexplore.exe processes running than there are open web pages, and, even more importantly,
    • Why would some of these processes produce high CPU usage and continue to grow in memory utilization up to nearly 1 GB.

    I understand that this may well be dependent upon the specific web pages, but I thought perhaps there were some IE configuration settings that could limit this.

    Monday, June 20, 2016 2:26 PM