Adrian: ***The 'other' meaning of thin client, is to run exe's that sit on the server at the workstation, this is how most capita software that I've seen runs. That was true I think of earlier versions of SIMS, Mentor etc. (we have come into SIMS.net via Mentor rather than the old SIMS). I don't know how other schools have SIMS.net configured, but here all the executables, dlls etc are on each station. My understanding is that there are no programs running on the SIMS server, so we're not talking about remote procedure calls, etc, we're talking about clients all of which directly access the SIMS database on the dedicated SQL server. Capita's efforts have gone into minimising the data transfers needed for the clients to construct data sets locally. But any database designer worth his salt would be doing that no matter whether 1 2 3 or whatever tier. Derek -- ******************************************************************************** All mail sent and received may be examined to prevent transmission of unacceptable material. Wellington College does not accept responsibility for email contents. Problems to postmaster@wellington-college.berks.sch.uk. Website: http://www.wellington-college.berks.sch.uk ********************************************************************************