How can I force the Windows Update application to check for updates and download them? I want the little yellow sheild to appear in the system tray and tell me "There are updates that have been downloaded and are ready to install" or whatever it says.

In other words, I want to simulate whatever happens at 3:00 AM every day (well, that's the default time). I'm guessing I need to send the right switch to wuauclt.exe?

why not just set the install time to like 5 minutes ahead of now. Then you'll see what you want to.

Hmm, well, I guess that would be better than nothing. How do I automatically change that setting?

And on the same note, how do I change the behavior of Windows Update? How do I choose "download and prompt me to install" instead of "download and install automatically"?

Edited September 6, 200520 yr by Nick2588

:: stop Automatic Update service
NET STOP WUAUSERV
:: Reset to force client to perform a detection cycle
REG DELETE "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /v LastWaitTimeout /f
:: start Automatic Update service
NEt START WUAUSERV

For prompt before downloading :

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update]
"AUOptions"=dword:00000002

@Bilou_Gateux:

Thank you for this script

wuauclt /detectnow

is the microsoft supported one.

On a related note, there's a wuauclt1.exe too but the date is July 2004, before SP2. What is it for?

@Takeshi

The file wuauclt1.exe is part of the "Background Intelligent Transfer Service". It retrieves Critical Updates for Windows and shows up on the task manager process list when its waiting for confirmation - for example to confirm permission to download a file.

Info found at Security Task Manager