I knew this was a requirement in previous versions of Windows Server and SBS, looks like we still have this in Windows Server 2012.

Disconnect UPS devices. If you have an uninterruptible power supply (UPS) connected to your server, disconnect the serial cable before you run Setup. Setup automatically attempts to detect devices that are connected to serial ports, and UPS equipment can cause problems with the detection process.

And while that is a good idea, a lot of times we’re sitting at our desks in one building and performing an upgrade on a server in a rack at an offsite location.  I’m all for a little exercise and walking over to the data center, but it just seems like with a couple of switches with the install process we should be able to tell our setup process that “No, we don’t want you to try to detect serial ports at this time and you should ignore the UPS until we can deal with it after the install.”

Wonder if this applies if our UPS uses a USB port instead of a serial port?