How can you tell for certain that Windows Updates have installed?

[msnews.microsoft.com]

How can you tell for certain that Windows Updates have installed? I can go
to the update site have the patches appear to download & then they start to
install. The progress bar might go half way across & sometimes stalls part
way across, so after say 5 minute wait when the bar doesn't move at all I
just shut down the PC. Are they installed or not? Will the update site
think that they are installed the next time I go to the site? Does the scan
for updates use cookies to keep track of what you have downloaded before &
if so should I delete these so that a new scan is done?

 

[johnf]

Windows Update, View Installation history
That shows all the successful ones.

 

[Guest]

For some reason i can view the installation history and not see some specific ones, so i also check, add n remove programs...and they are there

 

[johnf]

Yep, but it doesn't show there the ones that are not meant to - and can't be
uninstalled.

 

[Guest]

Is there anywhere on the machine stored what updates are installed? Appart from add and remove programs, which is not detailed and does not offer the possibility to save the information?