What is Microsoft's Windows 10 S and should I upgrade to Pro?

Windows 10 S is a streamlined version of Microsoft's Windows 10 operating system designed to improve performance by limiting the programs it can run.

The software can only run apps downloaded from Windows' Store, making it Microsoft's answer to Google's Chrombook.

Announced in May, the company has called the software a "walled" version of Windows 10 that will help computers "run as well as they do on day one as they do on day 1,000". One reason laptops slow down is invasive software, Microsoft says, so the new system will be welcome to many users.

However, the operating system restricts what apps users can download, meaning some users may want to stick to a more traditional program. For them, there is an option to upgrade to Windows 10 Pro for a $49 (£38) fee.

What is Windows 10 S?

Similar in many ways to Microsoft's current operating system Windows 10 Pro, the new software has the same task bars, multi-tasking and hot keys as the current system, as well as the same look. The operating system has been showcased on Microsoft's new Surface Laptop, released on June 15.

So what has changed? Apps installed on Windows 10 S are "contained" to prevent them from making changes to the operating system, which should mean the laptop performs better over its lifetime. Microsoft says the system should boot 15 seconds faster on average than a similar machine running Windows 10 Pro.

It also helps to secure the system by limiting the device to apps that are verified and downloaded through the Windows Store, which prevents malicious and unwanted software from slowing the system down.

The operating system is also designed to lock down and secure devices for use as education tools, tapping into the market that has been dominated by Google's ChromeOS.

Chrome and Firefox will not be available

One issue that may cause some people to change their operating system from Windows 10 S is the limitation of popular apps. The operating system limits users to Microsoft's Edge web browser and makes Bing the default search engine.

The restrictions mean users cannot set Google as their default search engine or download the Chrome app. Other search engines like Firefox aren't available either, while popular systems such as gaming platform Steam and Adobe's Creative Cloud Suite cannot be downloaded.

More apps are coming to the Windows Store, however, with Spotify and iTunes some of the latest additions. Any user attempting to install an app that is not approved by the Windows store will be met with the following pop up.

Should I upgrade to Windows 10 Pro?

If you really want to use apps that can't be accessed on the Windows Store you have the option of upgrading to Windows 10 Pro, Microsoft's current software.

The quickest way to upgrade to Windows 10 Pro is by attempting to download an app from outside of the Windows Store, which triggers a pop-up offering the upgrade.

The download will be free to users on the Microsoft Surface Laptop until December 31, after which users will incur a fee. The software upgrade cannot be reversed, meaning once you switch to Windows 10 Pro you cannot easily return to 10 S.

The update also won't be free on cheaper Windows devices, with those under $700 (£550) incurring a $49 (£39) fee for upgrading. Microsoft has not yet confirmed UK pricing.

What devices will run Windows 10 S?

The flagship device for Windows 10 S is Microsoft's new £979 Surface Laptop. It will also come on a range of new devices from Acer, Dell, HP Acer, Asus and Samsung. These devices will largely be cheaper than the Surface Laptop, although few are available in the UK at the moment.