Usually, there are two reasons why you cannot upgrade an old version of Windows to Windows 10. First, the old version of Windows (such as Windows 2000, XP, or Vista) is not supported by Microsoft as an in-place upgrade to Windows 10, and second, the computer hardware might not meet the minimum system requirements. So, you have no choice but to migrate your old version of Windows to Windows 10. A migration requires bringing in a new computer where you would install Windows 10. Once the installation of Windows 10 is completed on a new computer, you would want to run Windows Easy Transfer (WET) or User State Migration Tool (USMT) to move stuff from your old computer to a new computer. However, while WET is not available in Windows 10 (it was removed in Windows 8.1), USMT is intended for large-scale automated deployments.
Thus...
