Reboot / Shutdown Options – WuInstall Documentation

/install_cache "\\server\share\cache"

Prevents redundant downloads across machines on the same network by using a shared cache directory. Instead of every machine downloading the same updates independently, the first machine populates the cache and subsequent machines copy from it locally.

How it works:

WuInstall runs the standard search (same criteria and filters as /search)

For each update in the result list, WuInstall checks the cache directory for a subfolder named after the update's ID

Not in cache → downloads from WSUS or Windows Update, copies to the cache directory, then copies from cache to the local update cache

Found in cache → copies directly from the shared cache to the local update cache, skipping the internet download entirely

Cache copy fails → the cache subdirectory is deleted (assumed corrupt) and the update is downloaded fresh from the internet

Updates are installed after the cache/download step completes

Example — first machine (cache miss):

wuinstall /install_cache "P:\updates_cache"

Checking cache for update: Windows Malicious Software Removal Tool (KB890830) → Not found in P:\updates_cache\20110b11-6dd2-4153-a76d-e660ec78ebed → Downloading from Windows Update... OK → Copying to cache... OK → Copying from cache to local cache... OK

Example — subsequent machine (cache hit):

Checking cache for update: Windows Malicious Software Removal Tool (KB890830) → Found in cache directory, copying to local cache... OK

No internet traffic is generated for the second machine — the update is served entirely from the local network share.

/download_cache "\\server\share\cache"

Identical to /install_cache but stops after the download and cache population step — updates are not installed. Useful for pre-populating the cache before a rollout, so all machines benefit from cache hits from the start.

/nocachedel

By default, if copying an update from the shared cache fails, WuInstall deletes the cache subdirectory for that update and re-downloads it. Specifying /nocachedel suppresses this deletion, leaving the cache directory intact on error.

Use in combination with /install_cache or /download_cache.

/clearlocalcache

Clears the local Windows Update download cache:

%SystemRoot%\SoftwareDistribution\Download

Useful for freeing disk space or forcing a clean re-download of all pending updates.