What are you searching for updates?? Obviously using Windows update in Vista probably no longer works or it does not find anything. Don't understand what you are trying to do.
If you go to Start>Control Panel>Add/Remove Programs
In the Left pane you should see something about seeing Windows updates installed?? Don't remember, but that will show you all the updates installed.
By default Windows updates are kept;
C:windowssoftware\distributiondownloads
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