I have marked the update from Windows 7 to Windows 10. I had my X4 deleted, and new operating system Windows 10 installed. Now I downloaded X4, but it's not working. I need X4, what can I do? (I have serial number of my old x4 version).
Unfortunately, the X4 version is too old to be available for downloading, even if you still have a serial number. The application is available for purchasing through Amazon, if you still want it, but that means to invest in an outdated application.
I recommend contacting Corel: http://www.corel.com/en-eu/contact-us/ and after this procedure, try obtaining the latest version which benefits from support and maintenance.