I am on Windows 10 and the previous owner of this computer didn't fully reset it, and when I try to log in to the launcher it gives me the error code 
Error Code: 0x80004005 code: Eroded Badlands. A file that the Windows Product Activation (WPA) requires is damaged or missing. Please reboot, verify system permissions, and make sure your operating system is up- to-date. For more information, go HERE or contact Customer Support
directly. This time it's on Windows, not Mac. Once I got it to log in but then when my internet was fine it said "Unable to verify what products you own"