Acrosup64.dll Is Not Marked For Installation ❲UPDATED – HANDBOOK❳

Sometimes the DLL itself is correctly present, but its registration in the Windows Registry is broken.

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

If you prefer not to uninstall the software, you can attempt to force the Windows Installer to reset the state of the components. acrosup64.dll is not marked for installation

Warning: This step involves editing the Windows Registry. Incorrect edits can cause system instability. Proceed with caution.

If the error persists, the specific registry key for the component might be corrupted. You can attempt to locate the component key, but this is often difficult as the keys are GUIDs (random strings of numbers). A more practical advanced step is to re-register the DLL manually, though this is a workaround rather than a full fix. Sometimes the DLL itself is correctly present, but

The error message "acrosup64.dll is not marked for installation" is a common Windows Installer (MSI) failure typically associated with Adobe Acrobat or Adobe Reader. This error suggests a state mismatch between the Windows Registry and the actual file system, where the installer believes a patch or component is already present or improperly configured, preventing the installation, update, or uninstallation from proceeding.

To understand the error, you first need to know what the file is. Important: If the file is missing entirely, skip

When an installer checks for this file’s presence or registration state, the "not marked for installation" flag indicates a metadata mismatch in Windows Installer’s internal database.

Adobe provides an official tool to remove corrupted installation records. This is the first and easiest method.

Why this works: The Cleaner Tool removes orphaned registry keys and MSI references that cause the "not marked for installation" flag.