Plesk on Windows is running very slow and actions within the Plesk GUI are executed slowly

Symptoms

• Plesk Obsidian running on a Windows Server
• The Windows server has an antivirus solution agent such as Sentinel One, Sophos, Acronis Cyber Protect enabled and running
• Actions taken within the operating system itself are slow as well, not only actions within the Plesk GUI are running slowly
• The Windows Resource Monitor shows great spikes in CPU usage for the antivirus solution agent whenever any tab is pressed in the Plesk GUI:
  

Cause

The antivirus solution on the server is scanning every single Plesk-related process, because the Plesk-related directories mentioned in this article have not been excluded from the antivirus scanning process.

This puts the CPU under great strain and results in the slow performance of the entire server.

Resolution

Make sure all of the following directories will be excluded from the scanning actions of the antivirus agent you are using on the server:

• Plesk installation directory %plesk_dir% (with all its files and subdirectories).
• Plesk Installer directory - either C:\ParallelsInstaller or C:\ProgramData\Plesk\Installer (with all its files and subdirectories).
• The IIS (Internet Information Services) configuration directory C:\Windows\System32\inetsrv\config (with all its files and subdirectories).

Once constant scanning stops being performed for actions tied to these directories, your server CPU will not be overwhelmed.