Failed to read artifact descriptor Spring Boot

Downloading the jars and adding manually will not add the dependencies and child dependecies. Also the pom would not have been updated. Try deleting the following folders

org.springframework.boot:spring-boot-starter-jdbc 

org.springframework.boot:spring-boot-starter-data-jpa

from your maven repository(.m2) and refresh the maven project(ALT + F5).

Then u get can get the actual error(if exists) which u can post it here.