Since you cannot "install" it manually, you should verify if it is working correctly on your Windows 10 system: Windows Key + R to open the Run dialog.
Do not look for a standalone installer. The proper method to "update" or fix it is by running Windows Update to ensure your system is current. Version Verification: Windows Installer 5.0 Download For Windows 10 64-bit
Some very old installers check the OS version rather than the MSI version. Try running the installer in : Windows Installer 5