Open a Command Prompt and type slmgr.vbs /upk this will release your current license for re-use.
Having issues with downloading Microsoft Windows ISO files. The following method works to eliminate the requirement for having to use the Media Creation Tool. Windows 64bit and 32bit and a few other options to choose from. Saves you from the unsafe practice of downloading from unknown sources. Also works if you are getting the Error Code 0x80070456 – 0xA0019
I had to use internet explorer for this one but if you want a direct download from Microsoft of a Windows 10 32 bit, 64bit Home or Professional.
Open the page where the media creation tool is. https://www.microsoft.com/en-us/software-download/windows10
Selection Emulation Tab
At User Agent String select Apple Safari like the above picture.