All computers running Windows 7 or 8 can directly update to Windows 10 without having to reinstall the operating system. Unfortunately, the computer using another operating system such as XP, Vista are not supported to update to Windows 10. If you want to use Windows 10 computers with Windows XP, Vista, the only way is install the new one by CD or USB.
Upgrading the operating system is an extremely interesting job but sometimes spend too much time to reinstall the entire software or driver … Microsoft has announced that you can upgrade to Windows 10 from OS Windows 7 or newer. This means you do not have to reinstall the whole system, no need to backup data …
However, not everyone is so lucky, with the computer using the older OS like XP, Vista, you need to reinstall the Windows operating system via USB or CD. Representatives of Microsoft said that you needed to backup data and applications before installing Windows 10 to avoid losing data.
Windows Xp can't upgrade to Windows 10
In early May 10-2014, Microsoft officially launched their new operating system – Windows 10. This is the operating system completely changed people’s minds, it is “almost” agreed all devices together: laptop, mobile, tablet … After testing Technical Preview version, they’ve got plenty of positive feedback from users. This is the most powerful motivation to make them try their best to be ready for the upcoming release of Windows 10 by the end of this year.
If you are using Windows 7 or 8,8.1, let use the offical tools from Microsoft to be received the lastest notifications about Windows 10 operating systems  and ready to upgrade to the latest operating system from Microsoft.
For concern: At the end of this January (specific date 21-1-2015), Microsoft will have an event to introduce some new features of Windows 10 as well as share information about Windows 10 on the mobile device, tablet … You can see the official announcement in this article and watch live events at our Youtube offical channel.