I ran into a similar issue, and did some research. I found a script from MSDN, and modified it on my blog to automatically install updates.
You could run it with the cscript
command, available in every version of Windows since at least Windows XP, and put that command in your C# code to call this script. Posted below, save as a .VBS script:
Set updateSession = CreateObject("Microsoft.Update.Session")
updateSession.ClientApplicationID = "MSDN Sample Script"
Set updateSearcher = updateSession.CreateUpdateSearcher()
WScript.Echo "Searching for updates..." & vbCRLF
Set searchResult = _
updateSearcher.Search("IsInstalled=0 and Type='Software' and IsHidden=0")
WScript.Echo "List of applicable items on the machine:"
For I = 0 To searchResult.Updates.Count-1
Set update = searchResult.Updates.Item(I)
WScript.Echo I + 1 & "> " & update.Title
Next
If searchResult.Updates.Count = 0 Then
WScript.Echo "There are no applicable updates."
WScript.Quit
End If
WScript.Echo vbCRLF & "Creating collection of updates to download:"
Set updatesToDownload = CreateObject("Microsoft.Update.UpdateColl")
For I = 0 to searchResult.Updates.Count-1
Set update = searchResult.Updates.Item(I)
addThisUpdate = false
If update.InstallationBehavior.CanRequestUserInput = true Then
WScript.Echo I + 1 & "> skipping: " & update.Title & _
" because it requires user input"
Else
If update.EulaAccepted = false Then
WScript.Echo I + 1 & "> note: " & update.Title & _
" has a license agreement that must be accepted:"
WScript.Echo update.EulaText
WScript.Echo "Do you accept this license agreement? (Y/N)"
'strInput = WScript.StdIn.Readline
strInput = "Y"
WScript.Echo
If (strInput = "Y" or strInput = "y") Then
update.AcceptEula()
addThisUpdate = true
Else
WScript.Echo I + 1 & "> skipping: " & update.Title & _
" because the license agreement was declined"
End If
Else
addThisUpdate = true
End If
End If
If addThisUpdate = true Then
WScript.Echo I + 1 & "> adding: " & update.Title
updatesToDownload.Add(update)
End If
Next
If updatesToDownload.Count = 0 Then
WScript.Echo "All applicable updates were skipped."
WScript.Quit
End If
WScript.Echo vbCRLF & "Downloading updates..."
Set downloader = updateSession.CreateUpdateDownloader()
downloader.Updates = updatesToDownload
downloader.Download()
Set updatesToInstall = CreateObject("Microsoft.Update.UpdateColl")
rebootMayBeRequired = false
WScript.Echo vbCRLF & "Successfully downloaded updates:"
For I = 0 To searchResult.Updates.Count-1
set update = searchResult.Updates.Item(I)
If update.IsDownloaded = true Then
WScript.Echo I + 1 & "> " & update.Title
updatesToInstall.Add(update)
If update.InstallationBehavior.RebootBehavior > 0 Then
rebootMayBeRequired = true
End If
End If
Next
If updatesToInstall.Count = 0 Then
WScript.Echo "No updates were successfully downloaded."
WScript.Quit
End If
If rebootMayBeRequired = true Then
WScript.Echo vbCRLF & "These updates may require a reboot."
End If
WScript.Echo vbCRLF & "Would you like to install updates now? (Y/N)"
'strInput = WScript.StdIn.Readline
strInput = "Y"
WScript.Echo
If (strInput = "Y" or strInput = "y") Then
WScript.Echo "Installing updates..."
Set installer = updateSession.CreateUpdateInstaller()
installer.Updates = updatesToInstall
Set installationResult = installer.Install()
'Output results of install
WScript.Echo "Installation Result: " & _
installationResult.ResultCode
WScript.Echo "Reboot Required: " & _
installationResult.RebootRequired & vbCRLF
WScript.Echo "Listing of updates installed " & _
"and individual installation results:"
For I = 0 to updatesToInstall.Count - 1
WScript.Echo I + 1 & "> " & _
updatesToInstall.Item(i).Title & _
": " & installationResult.GetUpdateResult(i).ResultCode
Next
End If