You should also ensure that you have plenty of free hard drive space (20GB+). Before you begin, you should consider backing up your important files and documents, but it’s not really necessary. Once you have the Windows 8.1 ISO on your hard drive, the installation process is painless. Bear in mind that if you go down this road, upgrading to a real version of Windows 8.1 will require a few more steps (discussed in the next section). It’s not as snappy as the final (RTM/GA) build, though, and has quite a few bugs/missing features. The other easier, and completely legal, option is to download the Windows 8.1 Preview from Microsoft. (But do make sure that you’re checking the right SHA-1 hash on the MSDN website your ISO might be mislabeled). If it doesn’t, assume the ISO has been compromised and download another. If you then use File Checksum Integrity Verifier (FCIV) on the ISO, the hash should match. If you hit up the MSDN Subscriber Downloads page, and then click Details under the version that you’ve obtained from elsewhere, you’ll find the SHA-1 hash. While we’re not going to write a guide on how to obtain Windows 8.1 RTM from non-official sources, we will at least tell you to check the SHA-1 hash of the ISO that you download to make sure that it’s legitimate. If you don’t want to wait for October 17 or 18, there are two options for downloading Windows 8.1: You can obtain a copy (and a license key) from a friend/colleague with an MSDN, TechNet, or DreamSpark (student) subscription, or you can download a Windows 8.1 RTM ISO from your favorite file-sharing website (The Pirate Bay, Mega, etc.) To download and install Windows 8.1 for free, follow the guide below. If you’re using another operating system (Windows 7, Windows XP, OS X), you can either buy a boxed version ($120 for normal, $200 for Windows 8.1 Pro), or opt for one of the free methods listed below. If you’re using Windows 8, upgrading to Windows 8.1 is both easy and free.

Windows 8.1 installation id