I’m not 100% sure exactly what is wrong, but it sounds like the issue may be with Windows and not the software you are trying to install. I Googled the error and this came back:
“Windows Update error code “0x643” and Windows Installer error code “1603” are generic error codes. Typically, these error codes mean that the update was not installed. These errors codes are usually caused by a corruption in the . NET Framework installation or by an inconsistency on the MSI database state.”
Your download may be corrupted, or you might need to seek some repairs suggested in the above quote.
Running a “sfc /scannow” (without the quotes) from an administrative command prompt can some time fix corruption issues. If that doesn’t fix it, sometimes it could be out of date antivirus, or Windows may need to be refreshed. Sorry I cannot provide more help but it sounds like your issue is beyond the scope of this forum…