When you install Adobe Acrobat or Adobe Reader 7 or later on Windows, one of the following errors appears, and the installation quits:
- Error 1402: Could not open key [key name].
- Error 1406: Could not write value Folders to key [key name].
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. In addition, Adobe does not recommend installing both Acrobat and Reader on the same machine. You must have administrator privileges to complete these steps. For more information on administrator privileges, see the Windows documentation or contact Microsoft.
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Restart your computer and reinstall Acrobat or Reader.
Note: For Acrobat, reinstall the program from the Acrobat disk, or download the program from adobe.com. 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.
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.
Perform these steps during Acrobat or Adobe Reader installation. The Administrators group is the default local administrative group for Windows.
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Minimize the Registry Editor and click Retry.
- If the error reoccurs with the same key proceed to solution 2.
- If the error occurs with another registry key repeat steps 4-11 using the new registry key in the error message. You do not have to back up the registry again.
- If the error does not occur, finish the Acrobat or Reader installation by following the onscreen instructions. Exit the Registry Editor.
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Minimize the Registry Editor and click Retry.
- If the error reoccurs with the same key proceed to solution 2.
- If the error occurs with another registry key repeat steps 4-11 using the new registry key in the error message. You do not have to back up the registry again.
- If the error does not occur, finish the Acrobat or Reader installation by following the onscreen instructions. Exit the Registry Editor.
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Navigate to the parent of the key referenced in the error message. For example, for the key HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.pdf\PersistentHandler, choose Window > HKEY_LOCAL_MACHINE then open (double-click) SOFTWARE > Classes > .pdf.
Note: These steps may vary slightly depending on the path in the error message.

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Minimize the Registry Editor and click Retry.
- If the error reoccurs with the same key proceed to solution 2.
- If the error occurs with another registry key repeat steps 4-11 using the new registry key in the error message. You do not have to back up the registry again.
- If the error does not occur, finish the Acrobat or Reader installation by following the onscreen instructions. Exit the Registry Editor.
If Acrobat still displays an error message, you can investigate permissions on the particular registry key in question. Occasionally, renaming the key allows the installer to re-create the key and reset the permissions if the key is corrupted. If you can't change permissions or rename that key, contact Microsoft or your hardware vendor for assistance.
Note: Adobe provides this information as a courtesy only. Adobe Technical Support does not support third-party applications. You are encouraged to read the release notes for these applications before installing.
Scan for these programs with an anti-spyware utility such as Ad-Aware, available at www.lavasoftusa.com.
Use current anti-virus software, such as McAfee VirusScan, to check your system for viruses. Make sure that you have the latest virus definitions for the anti-virus software you use. For instructions, see the documentation for the anti-virus software.
For more information or help disabling Spy Sweeper, contact Webroot Corporation. Adobe technical support does not support third-party applications.
This McAfee software has been known to cause 1406 errors when installing Acrobat or Reader. For more information or help in temporarily disabling McAfee VirusScan 8.5 Access Protection, refer to the following article in the McAfee knowledge base:
https://kc.mcafee.com/corporate/index?page=content&id=KB52204
See if other users are experiencing similar problems by visiting the Adobe forums for Acrobat or Reader, or the Deployment & Installation forum on AcrobatUsers.com. 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.
Error 1402 occurs when the Windows installer is unable to read a particular registry key. Installation can fail because the Acrobat or Reader installer attempts to clean up registry keys of previous versions of Acrobat or Reader. This cleanup is necessary to avoid conflicts with Acrobat or Reader plug-ins and add-ins for third-party software.
Error 1406 occurs when the installer cannot successfully write a registry key essential for installation.