Error "The Adobe Acrobat/Reader that is running cannot … view PDF …"

When you view a PDF file on the web, the following error message appears: "The Adobe Acrobat/Reader that is running cannot be used to view PDF files in a web browser. Adobe Acrobat/Reader version 8 or 9 is required. Please exit and try again."

What's covered

Try this first

Repair current installation

Choose Help > Repair Acrobat Installation or Help > Repair Reader Installation.

Remove all previous versions of Acrobat or Reader, and then reinstall 

Adobe does not support multiple versions of Acrobat or Reader on the same machine. Because Acrobat and Reader work with many products, multiple versions simultaneously installed can lead to software conflicts and errors.

You must have administrator privileges to complete these steps. For more information on administrator privileges, see the Windows documentation or contact Microsoft.

  1. Do one of the following, depending on your version of Windows:

    • (Windows 7) Choose Start > Control Panel > Programs > Programs And Features.
    • (Windows Vista) Choose Start > Control Panel > Programs > Programs And Features.
    • (Windows XP) Choose Start > Control Panel, and double-click Add Or Remove Programs.
  1. Select Acrobat or Reader, and then click the option to remove or uninstall the program.
  2. Repeat the procedure for all installed versions of the program.
  3. Restart your computer and reinstall Acrobat or Reader.

    Note: For Acrobat, reinstall the program from the Acrobat disk, or download the program from For Reader, download the program from the Reader Download Center. If installing on Vista, right-click the Acrobat or Reader installer and select Run As Administrator.

More solutions

 1. (Advanced) Check the registry path for Acrobat or Reader 

Disclaimer: The registry contains system-related information that is critical to your computer and applications. Before modifying the registry, be sure to make a backup copy of it. Adobe doesn't provide support for problems that can arise from improperly modifying the registry. Adobe strongly recommends that you have experience editing system files before you modify the registry. For information on the Windows Registry Editor, see the documentation for Windows or contact Microsoft Technical Support.

  1. Choose Start > Run.

  2. Type regedit and click OK.
  3. Browse to the key HKEY_CLASSES_ROOT\Software\Adobe\Acrobat\Exe.
  4. Make sure that the (Default) value is set for the path where Acrobat or Reader is installed.

The default path for Reader is "C:\Program Files\Adobe\Reader 9.0\Reader\AcroRd32.exe."
The default path for Acrobat is "C:\Program Files\Adobe\Acrobat 9.0\Acrobat\Acrobat.exe."

Note: If Acrobat or Reader is installed in a different location than the default path, make sure that the key's (Default) value points to the actual location.

For a video demonstration of the procedure, go to

If the above registry item doesn't exist on the system, do the following:

  1. Choose Start > Run.

  2. Type regedit and click OK.
  3. Go to Edit > New > Key and create the missing HKEY_CLASSES_ROOT\Software\Adobe\Acrobat\Exe. 
  4. Go to Edit > New > String Value and name this key (Default).
  5. Select (Default), and then go to Edit > Modify. Type the default path (listed above) in the "Value data" for your product. 
  6. Restart your computer.

 2. Configure Acrobat or Reader as a helper application

With Acrobat or Reader configured as a helper application, the browser starts the helper application in a separate window and displays PDFs within that window.

  1. Start Acrobat or Reader.
  2. Choose Edit > Preferences.
  3. Select Internet on the left.
  4. Deselect Display PDF In Browser Using [Acrobat application], and then click OK.
  5. Quit Acrobat or Reader. 

 3. Run Acrobat or Reader in a new local administrator account

Create a user account that has the same permissions as the account you use when the problem occurs. Or, create a new local administrator account. If the problem doesn't recur when you log on to the new account, then the original user account could be damaged.

For information on setting up a user account, see "Create a user account" in Windows Help And Support, or contact your network administrator. For information on setting up a new local administrator account, see Create new local administrator account (Windows Vista).

 4. Visit the forums

See if other users are experiencing similar problems by visiting the forums for Acrobat, Reader, or If you don't see your issue listed, post it on the forums for interactive troubleshooting. When posting on forums, include your operating system and your product's version number.

Additional information 

This error can occur when the folder that contains Acrobat or Reader or one of its parent or subfolders has been renamed or moved. This error can also occur if Acrobat or Reader is not defined as the helper application within the browser.


Get help faster and easier

New user?

Adobe MAX 2024

Adobe MAX
The Creativity Conference

Oct 14–16 Miami Beach and online

Adobe MAX

The Creativity Conference

Oct 14–16 Miami Beach and online

Adobe MAX 2024

Adobe MAX
The Creativity Conference

Oct 14–16 Miami Beach and online

Adobe MAX

The Creativity Conference

Oct 14–16 Miami Beach and online