Level 1: Basic Repair (Success Rate: Low) Running the standard "Repair" utility from the Control Panel often fails because the installer hits the same logic error. However, it is the recommended first step.
Level 2: Adobe Cleanup Tool (Success Rate: High) Adobe provides a specific tool designed to resolve this exact registry state conflict.
Level 3: Microsoft Program Install and Uninstall Troubleshooter (Success Rate: Medium)
Level 4: Manual Registry Edit (Advanced)
acrosup64.dll is often loaded by the print spooler or a system tray app. acrosup64.dll is not marked for installation
If you have tried all six solutions and still see the error, the issue may be deeper:
In extreme cases, a Windows repair install (keeping your files) or a clean OS reinstall may be necessary—though very rare for this specific error.
Error Message:
acrosup64.dll is not marked for installation
Affected Software:
Adobe Acrobat / Adobe Reader (64-bit versions) on Windows Level 1: Basic Repair (Success Rate: Low) Running
Symptom:
The error appears during installation, repair, or update of Adobe Acrobat/Reader. The installer may roll back or stop without completing.
First, let's demystify the name. acrosup64.dll is almost always associated with Acro Software Inc. , specifically their CutePDF Writer or older versions of PrimoPDF. However, due to aggressive DLL packaging, it is often bundled into the installers of third-party OEM tools (Lenovo Vantage, Dell SupportAssist, or old HP printer suites).
The "64" denotes 64-bit architecture. The "sup" likely stands for "Support."
What it does: This DLL acts as a bridge. When an installer runs, it uses acrosup64.dll to verify dependencies for PDF generation or print spooling. The error "not marked for installation" means the installer's internal manifest (a map of what to copy where) explicitly lists this file, but the file's metadata within the installer lacks a specific flag that tells Windows Setup to actually unpack it. Level 4: Manual Registry Edit (Advanced)
acrosup64
Think of it like a grocery list: The list says "Buy milk." But next to "milk," there is no checkmark. The shopper (Windows Installer) sees the instruction but lacks the authorization to pick it up.
Once you resolve "acrosup64.dll is not marked for installation," follow these best practices to avoid recurrence:
Adobe provides a dedicated cleaner that removes all traces of previous installations.