For any number of reasons, you may need to create Windows 8.1 installation media. And now, thanks to a new online tool from Microsoft, you can. The Windows Installation Media Creation Tool lets you choose the language, product edition, and architecture, and then can save the resulting install media to a USB flash drive or to an ISO file, which you can later burn to disc if needed.
I'm not sure when this tool became available, but I know it wasn't around when Windows 8.1 launched. And it won't help you overcome some of the lingering issues with this release (like the inability to use a valid Windows 8.0 product key to install Windows 8.1 directly). But still it's very much appreciated.
Update: That's not true, apparently. According to several readers, this tool does work with a Windows 8.0 product key, which is wonderful. And it comes with Update 1 and Update 2 already integrated. Nice! --Paul
To get started, head on over to the Windows web site. Then, click Create Media to launch the Windows Installation Media Creation Tool.
In the first screen of this very simple wizard, you need to choose the following:
Language. English – en-us if you're in the United States.
Edition. Windows 8.1 (Core), Windows 8.1 N, Windows 8.1 Pro, Windows 8.1 Pro N, or Windows 8.1 Single Language.
Architecture. 64-bit (x64 ) or 32-bit (x86).
Then, click Next.
Here, you can choose between a USB flash drive or an ISO file. If you're doing this kind of thing a lot, my recommendation is download at least a few versions of this to ISOs and store them on a file share or USB drive somewhere so you can use them offline. But pick one or the other and click Next to create the install media.
A couple of notes.
You can't use this tool to create Windows RT install media, sorry.
If you received Windows 8.1 (or an older Windows version, too) with your PC, it probably came with a recovery partition or at least some tools for creating recovery media. You should always make that recovery media, even if you never intend to use it. You never know.
You should follow my instructions for creating Windows 8 recovery media too. It's the same in Windows 8.1, and you never know when you might need this. Check out Hands-On with Windows 8.1: System Recovery for more info. Oh, and this work for RT too.
And if you have a Microsoft Surface, Microsoft makes Surface-specific recovery images available for download from the Surface support site.