Question : How to update an entire field in MS Access on a regular basis

I have a table, access based, that is refreshed on a monthly basis with new data.  Some of the table's fields are data and some are currency values.  There is a data hierarchy from Ultimate Parent down through acount number.  One of the fields is descriptive of the Ultimate Parent.

Each month the descriptive field is replaced with not useful data.  I am trying to figure out how to run a query that can link an old table with the newest and replace the descriptive field in the new table with what is in the old.

I assumed this could be done through an update query, but I wasn't sure how to link.  I kept getting results that were saying the query was going to update way more records than were even in the table.

Answer : How to update an entire field in MS Access on a regular basis

I realized that the table i am linking to for the update can not have any duplicates.  When I use a condensed table and run the update query, it works fine.