This is what I use in one of my scripts.

code:
		$Hot = Dir("%SYSTEMROOT%\TEMP\Hotfixes")
		While $Hot <> ""
			If InStr($Hot,".") <> 1
			Shell '%comspec% /c %SYSTEMROOT%\TEMP\Hotfixes\$Hot /u /o /z /q'
			EndIf
		$Hot = Dir()
		Loop