Sometimes the Windows Installer service itself is out of date, leading to "not marked for installation" errors across various software. Go to . Click Check for updates . Install any pending updates and restart. Final Pro-Tip: The "Direct Download" Method
How to Fix the "acrosup64.dll is not marked for installation" Error acrosup64.dll is not marked for installation
If you've tried all the steps and the error persists, you may want to consider: Sometimes the Windows Installer service itself is out
"acrosup64.dll is not marked for installation" (often accompanied by Error 2753 acrosup64.dll is not marked for installation
A previous update may have crashed, leaving the registry in a "half-installed" state.
