Basic Functions

Basic Functions

WuInstall is built around three core switches. Every call must include exactly one — combining multiple switches (e.g. wuinstall /search /install) is not valid, since each operation implicitly includes the previous one:

1.1 Search

wuinstall /search

Lists all available updates for the current machine without making any changes. WuInstall queries either Windows Update directly or your configured WSUS server. Use this to audit what's pending or to validate filter logic before running a full install.

1.2 Download

wuinstall /download

Runs an implicit search, then triggers the Windows Update Engine to download all matching updates to the local cache. Note that WuInstall itself does not transfer the files — it instructs the Windows Update Engine to do so.

1.3 Download to Directory

wuinstall /download_to "C:\updates_download"

Extends /download by additionally copying the downloaded installation packages (typically .exe or .msi files) to a specified directory. Useful for manual installation, offline distribution, or staging updates for other machines.

1.4 Install

wuinstall /install

Runs a search, downloads any updates not already cached, and installs them. If /download was run previously, the cached updates are used directly and the download step is skipped.