SQL Server 2005 replaced with SQL Server 2014 trying to connect front end Access as guest (read only ODBC)

Question

We have replaced a SQL Server 2005 with a SQL Server 2014 (new physical server.)  Have the new server set up to use SQL Server login OR Windows user login. Had old server connecting (for a particular DB) to front end Access (2010 or 2013) as guest for
anyone logged into the Windows NT Network with a read only ODBC connection. Have the DB in the new server set to include guest as db_datareader (with only SELECT permission for the securables of each table and view being linked) but when any Windows user not
specifically listed as a SQL DB user tries to use the front end they get an error of:
Microsoft SQL Server Login
Connection failed:
SQL State: '28000'
SQL Server Error: 18456
[Microsoft][OCBC SQL Server Driver][SQL Server] Login failed for user {domain\user}.
After closing that pop-up window a server login window appears. Of course, since the guest user is not specifically listed as a user in the DB that fails also. It seems like there should be a very simple solution to this, but I can't seem to find it. I want
to allow anyone logged in on the Windows system (locally) to be able to open the MS Access file (on their work station machine) and run their own (read only; select) queries on the SQL Server database. Any suggestions?
Thanks a billion in advance ----

Answer 1

Thanks for the response Olaf. I have now spent weeks researching this. I realize that using the guest account in most situations is not advised. As mentioned, I have restricted the guest account to allow the db_datareader role only, and have explicitly denied
all other roles, as well as allowing select only, and still have no access for the guest account.
The suggested fix in the second link you provided, of using Windows groups is not plausible for my situation either. We are a scientific field research institution, with a few long term users and lots of users that may have Windows accounts for a few months,
and then they are gone. It would be a nightmare for the network tech to try to keep a group account up to date, and we need to give access (read only, of course) to anyone logged into the system. Realize that the ONLY access of any kind to this database is
thru MS Access ACCDB, using a (by default) read only OCDB connection.
This type of access is used particularly because researchers need to be able to set up their own queries, and the MS Access query interface is particularly convenient for people who are not themselves SQL experts, yet are trying to get some very advanced
levels of output. Putting the database online is not practical because then we are back to the need for a comprehensive query interface, and just picking up general subsets of the data online (from a basic web page search feature) would be out of the question,
since the result set would involve hundreds of thousands if not millions of records.
So - that said - what exactly would you suggest, assuming we don't have the funds to buy a whole new system, and have spent plenty of money with Microsoft's Enterprise level MS Office so that all work stations have MS Access, and Microsoft's SQL Server,
as well as running our network on Microsoft's network software.