• When performing a computer scan, you may occasionally see multiple (depending on product version) notifications in the Scan log such as "unable to open," "error opening" and/or "archive damaged"

Generally, your ESET product is unable to scan files that are displayed as "unable to open," "error opening" and/or "archive damaged" entries (depending on product version) in the scan log due to the fact that: 

• The file is password protected (for example, there are multiple user profiles on the computer)
• The file is a Windows system or program file
• The file is currently in use by other programs or background processes

Windows uses and locks certain files from startup until shutdown. These files and any others that are running in memory can't be used by or tampered with by other programs, including ESET products or potential malware. ESET does scan these files during startup and again during shutdown to ensure that they are not corrupt. If a locked file contains a threat, it will appear in red text in the scan log–files displayed in yellow are noted for informational purposes only and do not pose a threat to your system.

• Exclude a file or folder from Real-time scanning.