I’ve been using Windows 8 as a dual-boot option on my iMac for a while. When Windows 8.1 came out, I was pretty excited, as Peter Bright’s review on Ars Technica was quite positive about it.

Unfortunately, I was getting errors doing the upgrade it directly from the Microsoft Store, eventually getting Error 0x0073B92 - 0x20009. I was a little stumped about how to get around this.

The solution was actually simple: disconnect all of your USB devices during the installation. (Internet searching seems to indicate that this is related to a problem with a second hard drive).