Note to all Acer easyStore H340 WHS owners
What I should have done first is ask Google. She (that’s right, I picture Google as a smart, but seductive, oracle) has all the answers as long as I know what to ask.
It turns out that there is a bug with the WHS LightsOut plug-in that comes pre-installed on the computer. Just uninstall the app via Add/Remove Programs in the control panel and either update to the newest version here or run without it; I did the latter. More info about the bug can be found here and here.