Are you using "Preview Query", or "Run Query"?
If previewing, it just shows the CURRENT value of that field.
To actually update it, you have to Run the Update Query.
If that is still not working, here is a list of reasons why a query may not be updateable: http://allenbrowne.com/ser-61.html
Go through each one, and see if your query meets any of these conditions.
I tried to run and i got the error "you need an updatable query" (more or less..)
i thought my query was an aggregation query so i got the problem and i made another query based on first query and i had same problem
i created a new table and used it to update the table i wanted to update and everything went good, thanks
Glad to hear you got it working.
Yes, Aggregate (Totals) Queries are not updateable.
I suspect the reason, which one would find from that excellent link, is that there is no index in either table. Just because there's no PK field in either doesn't guarantee that, but I'd bet your money that a lack of any index was the issue based on the pics. Lack of primary keys or indexes in your db (or at least some of the tables) may prove to be an ongoing issue.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.