Windows Vista includes a Setup log which can be viewed and analyzed using Event Viewer. By default new Setup events generated are added to this log, but you can disable this functionality using local Group Policy as follows:
1. Type gpedit.msc in the Start Search box and hit Enter.
2. Click Continue when the UAC prompt appears.
3. Navigate to the following policy location:
Computer Configuration\Administrative Templates\Windows Components\Event Log Service\ Setup
4. Disable the following policy setting:
Turn on logging
Mitch Tulloch, MVP