Those of you eager to check out the new Windows 8.1 Preview have a few choices as to how and where to install it. Let's cut right to the chase and review the different options.
Update Windows 8
If you're already running Windows 8, you can simply update it to Windows 8.1 via the Windows Store, as CNET's Jason Cipriani explained earlier this week.
One word of warning before you proceed, however. The Windows 8.1 preview is essentially a beta of the new OS and is by no means a finished or polished version. Therefore, you shouldn't update to Windows 8.1 on your main or only PC. Instead, reserve the update for a spare or non-essential device outfitted with Windows 8.
Your first step in Windows 8 is to browse to Microsoft's Windows 8.1 preview page. Click on the Get it now button. At the Download Windows 8.1 Preview page, click on the Get the update button. You're prompted to open or save an msu file. You can open it directly or download it and then double-click on it to install it. You're then asked to install an update for Windows. Click Yes. After the installation completes, you're prompted to restart your PC.
Windows restarts to install the new update. Log back into Windows 8 at the lock screen. You should see a message inviting you to get Windows 8.1 Preview for free. Click on the link to Go to the Store where you can download the update...
Read the full story here. Source: CNET