List available system updates on Windows

list-available-windows-system-updates.ps1

# Description: Queries the Windows Update Agent (WUA) API to list all updates that are available for installation.

# Create an Update Session COM object (entry point to Windows Update API)
$Session = New-Object -ComObject Microsoft.Update.Session

# Create an UpdateSearcher to query for available updates
$Searcher = $Session.CreateUpdateSearcher()

# Search for updates where IsInstalled = 0 (i.e., not yet installed)
$SearchResult = $Searcher.Search("IsInstalled=0")

# Process and display each update in a formatted table
$SearchResult.Updates |
Select-Object (
    'Title',  # Name of the update
    @{ Name = "KBArticleIDs"; Expression = { $_.KBArticleIDs -join "," } },  # Concatenate all KB IDs
    'IsMandatory',  # Indicates if the update is mandatory
    'BrowseOnly',   # True if the update is only visible in the optional section of UI
    @{ Name = "Categories"; Expression = { $_.Categories | ForEach-Object { $_.Name } -join "," } },  # All associated categories
    'Type'  # Type of update (e.g., Software, Driver, etc.)
) | Format-Table -AutoSize  # Neatly format the output