My objective is to learn and practice all the vulnerabilities and their exploitation on vulnerable OS.
Rapid7's Metasploitable3 is a great resource and is intended to provide you with vulnerable Windows machines you can exploit with tools such as Metasploit (I recommend also trying to exploit these using other more manual means as well).
You may also be interested in DetectionLab which is a small Windows Active Directory lab that focuses more on defense but can be used as an overall red/blue team playground with more modern operating systems.
Both contain well-documented instructions on setup.
Not sure why everyone is saying there is no way to get free licensed Windows versions, since Microsoft provides VM Appliances expressly for security and dev testing purposes at https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/ They currently have 90 day licensed versions of Win 7 through 10, all of which have unpatched vulnerabilities to exploit. Simply save a snapshot after activating so that you can restore it when the license expires. Before anyone questions the legality here, see Microsoft's instructions regarding extending the 90 day licenses, "These virtual machines expire after 90 days. We recommend setting a snapshot when you first install the virtual machine which you can roll back to later. "