Upgrade Windows 7 on Z390 to version 10 in a fresh build.
Upgrade Windows 7 on Z390 to version 10 in a fresh build.
You might face some issues when installing Windows 7 on your Z390 motherboard while keeping your Windows 7 disk and key. Upgrading to Windows 10 could help avoid these problems.
Create a USB drive with the newest Windows 10 ISO file and follow the installation steps to set it up.
Setting up Windows 7 should be quite challenging. It might be better to switch to Windows 10 and see if the key works. Paul from Paul's Hardware shares his experience, noting that it sometimes succeeds and other times fails.