Does anyone know what might cause a SQL Server DSN that has been working for years suddenly stop working? Yesterday, one of my legacy apps (designed and running on Access 2007) stopped working (ODBC connection failed). When I went to check the DSN configuration, I was told over and over again that the login failed (the same login that has been in use since about 2010 or so). I am the only person who has access to the inner workings of this application and the database (SQL Server 2008 R2 Express) that feeds it and I haven't changed anything since 2010 (when the same thing happened).
I thought a Windows Update might have been the culprit so I did a system restore to reverse it, with no luck. All I could do was create a new DSN and then go through the very tedious process of updating all my linked tables and (even more tedious) updating the connection string on over 100 pass through queries. I'd sure like to know what's causing this and how to avoid it in the future.