You shouldn't have any problems connecting to SQL Server either with an .ADP or .MDB version database. We do it all the time. If you are using ODBC, then you will want to get the appropriate SQL Server Native Client - unless you are running Win7 on workstations (it already has the latest version for all except SQL Server 2012. (BTW, the 64 bit version of Access 2010 is less stable than the 32-bit version.)