The message typically appears when using Microsoft’s MSI (Windows Installer) technology, often during software installation, repair, or update operations. It indicates that the installer is trying to access or install a specific file ( acrosup64.dll ) but the file component is not flagged in the installation package’s internal configuration as needing to be installed under the current context.
msiexec /i "path\to\installer.msi" /L*v "C:\temp\install.log" Then search the log for acrosup64.dll . You will see a line like: acrosup64.dll is not marked for installation
msiexec /unregister msiexec /regserver Then retry the installation. If you know the feature containing acrosup64.dll (e.g., “Acrobat Main Program”), set it to “Run all from my computer”: The message typically appears when using Microsoft’s MSI