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Windows Automatic Update Client Command Line Switches
wuauclt:
/r or /reportnow /a or /resetauthorization /detectnow /? or /h or /help
Force an Update
wuauclt.exe /a /detectnow
Force a client to report to the WSUS server
wuauclt.exe /r
WSUS 3.0 SP1 Tips
1) Make sure Disk Quotas are disabled on the drive where you host the WSUS update files. Otherwise the MMC snap-in will fail with an "Out of disk space" error.
2) If you install WSUS 3 SP1 on port 8530, the SelfUpdate virtual directory isn't created. You will have to manually create the SelfUpdate virtual directory and point it to C:\Program Files\Update Services\Selfupdate (leave the default permissions)
Reference: Error 0x80244019 After Installing WSUS SP1