nonWSUS

NonWSUS, also known as WSUS Offline, is a free and open-source tool designed to enable Windows operating systems to receive security updates from Microsoft via a local cache, without requiring the use of the Windows Update service (WSUS) or an active internet connection.

The tool was initially developed as a workaround for environments where internet connectivity is unreliable or not available at all, or when attempting to keep Windows systems up-to-date in situations where WSUS infrastructure is not feasible to set up or maintain. NonWSUS allows installing, downloading, and caching Microsoft security updates from a local source.

A user of NonWSUS must have a connection to the internet beforehand to download the available updates. The tool then packages these updates and makes them available for subsequent offline installation on Windows clients. When the tool is run again, it creates a snapshot of the current state of the local update cache, which can then be served as a fall-back for future offline updates.

Overall, NonWSUS serves as an efficient and practical alternative to WSUS, which operates under the same principle of pre-emptively storing security updates locally. The tool's key feature is the offline distribution of updates, achieving a similar function but for individual workstations, avoiding the need for centralised server systems.