If you own a Windows device, chances are you've received a notification about Windows 10. The operating system became available one year ago and Microsoft has allowed customers to upgrade for free. That generous offer expires today, however. 

If you own a device running Windows 7 or Windows 8, you can upgrade today for free. If you want to upgrade, simply click here. 

Before you do that, however, take some time to back up all of the important information stored on your device. You can either save your files to something like Dropbox or save to an external hard-drive (should you have one lying around). 

If your device runs Vista, or any earlier version of Windows, you're out of luck unfortunately.

Device running Windows 7 or Windows 10 need to have a certain level of tech-spec for the upgrade to be successful.