Adobe Reader 8.1 problem – AdobeUpdater.exe running at 100% CPU

I encountered a problem after updating Adobe Reader to version 8.1 where the AdobeUpdater.exe process would run at near to 100% CPU. I was unable to end the process in the Windows task manager despite repeated attempts.

The impression I received from reading about the experiences of other people with this problem is that is related to certain firewall software products not allowing AdobeUpdater to connect to the internet. Updating my firewall settings to allow this process full access to the internet did not resolve the problem.
If you are suffering from the AdobeUpdater process as well I can suggest four possible solutions:

  1. Review and update your firewall settings to allow the AdobeUpdater process to access the internet.
  2. Install an earlier version of Adobe Reader.
  3. Try installing alternative PDF viewer software such as FoxIt Reader.
  4. Prevent the AdobeUpdater process from running, detailed below.

Fix the AdobeUpdater problem – when you have Adobe Acrobat 8.1 (not the free version)

If you want to continue using Adobe Acrobat but have a problem with AdobeUpdater causing your computer to run slowly there is a work-around described here, as excerpted from the discussion on the Adobe forum here – AdobeUpdater.exe hogging all the CPU runtime (the solution is highlighted in bold text).

Hi Pam,

Sorry my message wasn’t clear, I copied it from another post.

What I did was to rename ‘Updater.api’ in C:\Program Files\Adobe\Acrobat 8.0\Acrobat\plug_ins to ‘Updater.api.PROBLEM‘ (subtle, eh?)

That way, Adobe can’t find the updater program to run it. I’ve had this fix in place since the 26th Feb and I’ve had no recurrence of the CPU problem and apparently no problems caused by my fix either.

Hope that helps.

Best regards,


Fix the AdobeUpdater problem – when you have Adobe Reader 8.1 (the free PDF reader)

If you are using Adobe Reader 8.1 (the free PDF reader) and you want to stop the AbobeUpdater process from running then the instructions are slightly different to if you are using Adobe Acrobat.

The following screenshots will show you how to rename the Updater.api file. These are taken from a computer running Windows XP.

Step 1 – Open the ‘Run…’ command.


Step 2 – Enter the following in the ‘Open:’ field :
C:\Program Files\Adobe\Reader 8.0\Reader\plug_ins


Step 3 – Right click on the Updater.api file, and select the Rename option.


Step 4 – Rename the file to Updater.api.PROBLEM and press the Enter key.


This big downside to this workaround is that you will miss out on notification of new releases and updates. It’s not a perfect solution but it’s the only I found that let me continue to use Adobe Acrobat 8.1.

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Comments (3) to “Adobe Reader 8.1 problem – AdobeUpdater.exe running at 100% CPU”

  1. I am having the same issue with Adobe Reader. I cannot open the program since the update to 8.1. It brings up an error saying that it encountered a problem and needs to close. Then it freezes everything and I have to use Task Manager to end the program. Disabling my firewall did not fix the problem. Installing an earlier version fixed it. Thank you for the advice.

  2. My pleasure Stefanie! I’m glad you were able to fix the problem.

  3. [...] The second lesson to learn: if your product messes up someone’s computer – expect them to stop using your product. Luckily I found some posts and a some kind of solution to this problem (renaming file “updater.api” for example to “updater.api.PROBLEM”) and may continue using the reader. If there wouldn’t been a solution, I would have got some other reader. Rest assured your players will stop playing your game if it crashes their computer. [...]