Windows Vista: Start Windows Update via script in Audit Mode
Windows Update is not enabled by default in Audit Mode.
This CMD script will enable it and check for updates:
NET STOP "Windows Update"
REG ADD "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /v AUOptions /t REG_DWORD /d 00000004
REG ADD "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /v ScheduledInstallDay /t REG_DWORD /d 00000000
REG ADD "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /v ScheduledInstallTime /t REG_DWORD /d 00000003
NET START "Windows Update"
WUAUCLT /DETECTNOW