You can try to install EQ6 however, unfortunately, EQ6 will not always install on Windows 10. If you are having trouble installing EQ6 please make sure that Windows 10 is up to date. EQ6 was originally designed for Windows XP and updates to the Windows Installer’s security policy in Windows 10 sometimes prevent it from being installed.
If you have EQ6, and cannot install on Windows 10, an option would be to buy EQ8.
Note: You do not need any prior versions installed before installing EQ8.