Launch the program and select your specific software track (Acrobat or Reader).
You cannot delete the old file normally. You need to take ownership. acrosup64.dll is not marked for installation
Type cmd and press Ctrl + Shift + Enter to open an elevated Command Prompt. Launch the program and select your specific software
If this error appears during an automated deployment (SCCM, GPO, MSI), it is usually because an older version of the file exists on the machine. the installer payload can corrupt
Online installers download fragments of data dynamically. If a network packet drops, the installer payload can corrupt, triggering the "not marked for installation" error.