Acrosup64.dll Is Not Marked For Installation Now

Resolving the "acrosup64.dll is not marked for installation" Error: A Comprehensive Guide

Encountering a cryptic error message during software installation or uninstallation can be frustrating. One such error that plagues users—particularly those working with Adobe Creative Cloud applications (like Photoshop, Illustrator, or Acrobat) on 64-bit Windows systems—is: "acrosup64.dll is not marked for installation."

This message typically halts the installation process, rolls back changes, and leaves software either partially installed or completely missing. Before you panic or consider reinstalling your entire operating system, understand that this is a known issue with a set of specific, fixable causes. acrosup64.dll is not marked for installation

In this guide, we will break down what this error means, why it happens, and—most importantly—step-by-step solutions to permanently resolve it. Resolving the "acrosup64

Write-Up: AcroSup64.dll “Not Marked for Installation” Error

3.2. Manually Fix MSI Component State (Advanced)

Open regedit and navigate to:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\[User SID]\Components
Search for acrosup64.dll.
If found with an incorrect state, delete the related component key only if fully uninstalled — else use msizap (Microsoft tool) cautiously.

Solution 3: Manually Deregister and Register the DLL

Sometimes the DLL itself is correctly present, but its registration in the Windows Registry is broken. Solution 3: Manually Deregister and Register the DLL

Open Command Prompt as Administrator (search cmd, right-click, run as admin).

Navigate to the folder containing acrosup64.dll. Typical paths:

cd "C:\Program Files\Adobe\Acrobat DC\Acrobat"

Or for Reader:

cd "C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader"

First, unregister the DLL:
```
regsvr32 /u acrosup64.dll
```
Then, re-register it:
```
regsvr32 acrosup64.dll
```
You should see a success message. Restart your PC.

Important: If the file is missing entirely, skip to Solution 5.