Microsoft Windows Server 2003 and Microsoft Windows Server 2003 R2 came with built-in support for serial and USB connected Uninterruptible Power Supply (UPS) devices. From within the Power Options you could manage your UPS and the shutdown behavior of the box.
However, Microsoft Windows Server 2008 doesn’t offer this built-in support anymore. You’ll need to install the software from the UPS manufacturer to benefit from advanced shutdown behavior, calibrate the UPS device. The upside to this story is these software packages support UPS devices, connected using network connections, USB connections and through serial connections. These software packages also allow for a connected Windows servers to send alerts to other Windows servers to perform actions.