The information you offered is too less for analysis, please share us SQL server 2019 summary and detail setup log as Erland mentioned. We may find which key blocked this installation.
Did you have any previous failed SQL 2019 installation? Did you delete the failed installation completely? You can refer below steps;
Uninstall the existing SQL Server and all the components from the add remove program.
Backup the registry.
Delete the following keys using regedit:
o--HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server
Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall and delete all the sub-keys referencing SQL Server.
Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services and delete all the keys referencing SQL Server.
Rename all the SQL Server folders in the computer.
Reboot the machine.
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