Download the standalone enterprise distribution package from the Adobe Acrobat Reader DC Distribution page.
Attempting to install a 64-bit patch over an older 32-bit baseline installation of Adobe software.
Enterprise packages bundle all dependencies securely within standalone setups. Use the official Adobe Acrobat Reader DC Enterprise Distribution Platform to grab the complete standalone installer suite. Step 2: Extract and Execute Manually via Command Line acrosup64.dll is not marked for installation
By methodically working through the solutions above, you will clear the error, save hours of frustration, and get back to using your Adobe software normally. Always remember to back up critical data before editing the registry or running system-level repairs.
The most effective way to fix this is to completely wipe the slate clean. Standard uninstalls often leave behind the very registry keys causing the conflict. Use the official Adobe Acrobat Reader DC Enterprise
This issue happens when the Windows Installer database gets confused, usually because of leftover registry keys, corrupted files, or a mix-up between old 32-bit and newer 64-bit Adobe components on your computer. Comprehensive Comparison of Fixes Best Used For Success Rate Technical Level Standard users experiencing update or installation blocks. Manual Directory Purge Persistent errors where the cleaner misses hidden app data. Registry Cleanup Enterprise rollouts, GPO failures, or stubborn MSI blocks. Offline MSI Extraction SCCM/IT administrators and managed corporate environments. Step-by-Step Solutions to Fix the Error
If the cleaner tool doesn't work, manual removal of cached files may be necessary: Uninstall Adobe via the Control Panel Navigate to C:\Users\%username%\AppData In each of the folders, find and delete the Restart your PC before re-attempting the installation. 3. Advanced Registry Cleanup (For Experienced Users) The most effective way to fix this is
: acrosup64.dll is a support file for Adobe Acrobat/Reader, often related to 64-bit shell extensions or synchronization. Alternative Fixes error the file acrosup64.dll is not marked for installation
(common for Adobe products) or any folder that mentions "Adobe" or "Acrobat" inside its registry values.