Windows 8.1 is already available Thursday for Windows 8 devices and users can have a free upgrade by simply downloading it from the Windows Store.

It is tempting to switch to the updated Windows 8.1 version just like how it was tempting to get Apple iOS 7 downloaded when it came out. However, opting to upgrade to the new OS may not be as easy as it seems especially for those who have a number of personal computers or laptops to manage and for those who have installed Windows 8.1 preview before.

So if you are one of those who have multiple computers or devices running on Windows 8.1 Preview before, the Register listed a few things to consider before you upgrade.

One device, one download

First, you can’t do just one download and have it applied on all your computers and devices. You have to install Windows 8.1 on each of your device.

“The Windows Store is the only way for consumers (non-enterprise, non-IT Pro) to download and install Windows 8.1. No ISOs will be made available, so each device needs to be updated individually via the Windows Store,” said Microsoft told Register when they asked for clarification.

Windows 7 to Windows 8 costs

Getting Windows 8.1 is just simple. Users can just visit the Windows Store and get it from there, but mind you, downloading and installing it is a little annoying. Not just that, if you are updating to 8.1 from Windows 7, you won’t get it for free. Users will have to pay $120 for the standard version and $200 for Windows 8.1 Pro.

3.5GB storage required

The size of the new OS varies depending on what OS you have on your computer, but the upgrade is roughly 3.5GB, so it will surely take time and you will need a stable internet connection. Good news is, if the downloading is interrupted, you can resume from where it stopped by going to the Windows Store again.

Refresh deployment for enterprise

Enterprise customers, luckily, can get the update a little easier than the other customers. Since enterprise customers have the Volume Licensing (VL) versions, the installation can be done by in-place updates over existing Windows 8 OS, unlike small computer shop owners wherein they have to download the update one by one on each computer.

Enterprise system administrators can prefer to do "refresh deployment" also. Refresh deployment is where "data and settings are captured, the current OS is removed, Windows 8.1 is installed on a clean drive, apps are reinstalled, and then the user data is restored. Unfortunately, only those with VL versions can do these methods.

The downside for those who have installed Windows 8.1 Preview before is when they choose to upgrade to the new Windows 8.1, all their apps will be trashed including Windows Store apps and desktop applications and they would need to reinstall them again.