1. Where is SQLServer running? Is it on the same file server that the .mdb file was on or was it on another server? Is the other server located in the same facility as the file server?

2. What results do you see when you use SQL Server Management Studio? SQL Server MS is GUI interface that allows you to work with a database directly in a manner similar to Access DB window. If you run a query in Management Studio, the performance should be similar to that when the same query is run in Access. For the sake of testing, try a simple query such as selecting the Top 100 rows of a table.

3. Do the Access forms use query objects or is the SQL Statement explicity stated in the RecordSource of the form? Now that you've upsized to SQL Server, you do need to go through and check all of the queries and RowSource's of the Forms & Reports and shift the work of doing table JOIN's to SQL server via Views. When Access does a join, regardless of the backend database, that adds overhead right off the bat. It has to do them when connecting to an Access DB, however it can all be shiftted to the backend when using a commerical database such as SQL Server.

Side Note: If you have tables that the users should NOT be able to update that should be READ ONLY, create a stored procedure that returns the records in that table.