How can you manually begin Windows XP's Windows Update without entering to http://update.microsoft.com/windowsupdate with IE?
From command line, force detect with:
To troubleshoot machines updating from my WSUS server.
I am not sure if it will apply to normal online updating but it is worth mentioning.
Troubleshoot update issues with this logfile:
If you are using Windows 10, Windows updates are logged with ETW (Event Tracing for Windows): https://support.microsoft.com/en-us/kb/3036646
Another way to manually begin the windows update procedure in XP is to restart it from the Control Panel:
This forces Automatic Updates to restart, and the result can be seen in the logfile
This is also a great way to restart AU downloads if they have been interrupted for some reason.