MSI Error 1603: Fatal Error During Installation and How to Find the Cause
Error 1603 is Windows Installer’s catch-all fatal error. Read the verbose log for the action that failed, and check the four causes Microsoft documents.
Kaspersky install error 1721 and 1327: setup fails on this Windows machine
Kaspersky error 1721 stops installation when Windows Installer or a rival antivirus gets in the way. See the cause and the clean install route.