Before explaining how to set up data gathering, it is important to explain an important issue related to available data sources in the ConfigMgr server. There are two kinds of data and two databases: a WMI and an SQL database. While creating reports, queries will reference different databases.
Note
To show the same data in the query as well as in the report, you need to perform two different queries, one to the WMI database and the second one to the SQL database. It is especially fiddly for new administrators, as you need to do the same work twice.
The ability to create queries and reports doesn't mean much if the administrator will not be able to get to the interesting data. Sometimes it is fairly easy, as the server collects a default set of data; however, there are moments when there is a need for manually adding some data to be collected.