Install Adobe Acrobat Prof encountered error msg on Windows 11 25H2

Hello Tan Tiong Hin (NSS),

The error message you’re seeing (Error 1406) typically indicates that the installer is unable to write to certain registry keys due to permission restrictions.

Even though you’re using an administrative account, registry permissions can sometimes be locked down by domain policies or inherited security settings. A good first step is to run the installer explicitly as Administrator (right-click > Run as Administrator). If the issue persists, you may need to adjust the permissions on the specific registry keys mentioned in the error message. Using the Registry Editor, you can right-click the key, select Permissions, and ensure that Administrators have Full Control.

It’s also worth checking if any endpoint protection or security software is interfering with registry writes. Temporarily disabling such tools during installation can help rule this out. Another option is to perform the installation in Safe Mode with Networking, which reduces background interference.

Lastly, Adobe provides a cleaner tool that can remove remnants of previous installations. Running that before reinstalling often resolves stubborn registry conflicts.

I hope the response provided some helpful insight. If this answer is helpful, please don’t forget to hit “Accept Answer”.

Jason.

Error 1406 during Adobe Acrobat installation indicates a permissions problem writing to specific registry keys under HKLM\Software\Classes. The issue is with Adobe’s add-in/COM components, not with Windows 11 itself.

Because the failure is tied to Adobe’s Office/Acrobat integration (AcroPDF, AppID GUID), the supported path is to work with Adobe’s guidance and tools to correct permissions or remove/reinstall their Office/Acrobat add-ins. The recommended approach is:

1. Treat this as an Adobe add‑in/Acrobat installer issue rather than a Windows 11 25H2 issue.
2. Use Adobe’s official troubleshooting steps or contact Adobe Support/Acrobat Community for the current registry locations and permission fixes for the AcroPDF and related keys.
3. If the error appears when Office is involved (for example, PDFMaker or SaveAsAdobePDF components), remove or repair the Adobe add‑in for Office using Adobe’s installer, then retry the Acrobat installation.

Do not manually modify or delete registry keys unless following Adobe’s documented procedure, as incorrect registry changes can cause serious system and Office/Acrobat problems.

References:

• how do I if the error run-time error 53 on 365 that I just purchased - Microsoft Q&A
• Are there known problems with Tahoe and Adobe - Microsoft Q&A
• Word does not save changes or you receive an error message in an Office program after you install Adobe Acrobat 7.0