Outlook 2010–High CPU Usage <Solved>

I noticed yesterday that whenever I had Outlook 2010 open on my home PC that my CPU utilization was very high.  Outlook appeared to be taking up 50% of my processor.  I had no idea why it was doing this, and I wasn’t sure how long it had been doing so.  I rarely use Outlook since I manage most of my emails via my smartphone, so it could have been doing this for weeks.

I have Outlook hooked up to my Exchange server (hosted locally), plus a Gmail and a Hotmail account.  I checked my Exchange connections to see if there was anything pending, but every connection seemed to be stable.  Eventually, I selected “Work Offline”, which had no effect immediately.  However, I then closed Outlook and re-opened, and the CPU utilization seemed to be normal.  I then unchecked “Work Offline”, and immediately my CPU spiked back up (and stayed there).

Next, I started Outlook in safe mode (by executing “outlook.exe /safe” from the Run prompt).  The CPU utilization was fine.  I was then convinced that the problem was one of my many Outlook add-ins.  I proceeded to move through my list of add-ins, disabling one, restarting Outlook, checking my CPU usage, then disabling the next add-in, and so on.  I was worried when I saw there was an add-in referring to Exchange.  I was hoping this wasn’t causing the problem, since I need to be able to access my Exchange account.  However, this wasn’t the problematic component, and it turns out that add-in is only for Unified Messaging features, anyway (something I don’t use on my Exchange box).

Finally, I came to the Outlook Social Connector add-in.  This is the plug-in that allows Facebook, Linked-In, etc. to integrate with Outlook.  I was unable to disable the add-in without Outlook locking up (which was awfully suspicious), so to disable it, I exited Outlook, browsed to the file location that Outlook listed for that add-in, then renamed it to .old.  For anyone wondering, the location for me was: C:\Program Files (x86)\Microsoft Office\Office14\SOCIALCONNECTOR.DLL.  If you’re running the 64-bit version of Outlook, or if you’re NOT running a 64-bit version of Windows, the file location would be: C:\Program Files\Microsoft Office\Office14\SOCIALCONNECTOR.DLL.  Once I restarted Outlook my CPU utilization was normal.

Now, the Social Connector isn’t a mandatory part of Outlook for me, but it’s nice to have, so I decided to attempt to fix the issue.  First, I went into the Outlook add-ins dialog and removed the add-in.  Next, I wanted to re-install the Social Connector, but couldn’t find the installer in Programs and Features.  Then I remembered that the RTM version of Office 2010 ships WITH the Connector, so to re-install the add-in, I’d need to run a repair install of Office.

Before running the repair install, I first decided to remove the Facebook, Linked-In and MySpace (not that I use that one anyway; it can stay off) Social Connectors.  These are listed individually in Programs and Features (which is Add/Remove Programs, for you Windows XP users).  Once I removed those, I then ran a repair install of Office.  After that finished, I launched Outlook, checked to see if the Social Connector was enabled (which it was), then exited and installed my Facebook Connector, re-launched Outlook, and voila!  Problem solved.

While it may not be entirely necessary to rename the SocialConnector.DLL file .old, I highly recommend it, as the Office repair installation may skip over the file if it detects it’s still there.  By renaming it, you’re ensuring you get a fresh copy of the proper file.

TL;DR: Outlook Social Connector was the culprit for high Outlook CPU utilization.  Rename the add-in’s DLL file (SocialConnector.DLL) to .OLD, run a repair install of Office, ???, PROFIT!!!

Written By drew

9 Comments on “Outlook 2010–High CPU Usage <Solved>

  1. jazzwhiz Reply

    October 10, 2010 at 2:35

    3) teach monkeys to joust

  2. Jere Reply

    January 31, 2011 at 6:35

    Thanks, disabling the Social Connector is the solution!

  3. moen Reply

    June 8, 2011 at 9:33

    thx, seems to solve the issue so far, but still waitin how it will behave

  4. Neil Reply

    September 6, 2011 at 9:17

    how do you solve it if the CPU usage is low in safe mode, but high in normal mode?

    • drew Reply

      September 13, 2011 at 7:52

      If it’s high in normal mode, that means it’s an add-on causing the problem. Go through the steps I listed and try to identify the problematic add-on.

  5. Kris Stevens Reply

    June 20, 2012 at 3:23

    I am glad you solved your problem and tried it with my Windows 7 Ultimate, 64-bit o/s. I have Outlook 2007..couldn’t find the 2011 when I had to rebuild this replaced HP All-In-One Desktop. Last week I was warned of the high CPU usage. Today I decided to tackle it and found your site. It was very helpful, but I do not have a socialconnector.dll on this system. I did however remove my facebook entry under install programs but that did not help.

    I set the gadget meters to always be on top. When I opened Outlook it went sky high. Outlook also does not close all the time, so I have to go to task manager and shut down the process. That worked. The meter went back to normal, so I was lucky to find the problem so fast. Now I have to find out what to do about it. Do you have any ideas?

    Thank you for taking the time to document your ordeal.


  6. Guimms Reply

    August 28, 2012 at 10:38

    [Vista 32bits + Outlook 2010]
    Disabling the social connector did the job.
    Will try the repair part in a few days.
    Many Thanks.

  7. Matt Reply

    April 19, 2013 at 2:47

    Thank you! I’ve had this exactly same problem for ages. Some days Outlook would work just fine but often it would use little under 10 % processor constantly. Renamamig that social connector dll seems to have solved the issue.

  8. Jack Reply

    December 1, 2017 at 1:09

    hi thanks a lot, disabling one of the IM (Instant Messaging) related addin did the trick for me. Win7(64bit), Outlook 2010(32bit)

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