Install MongoDb 2.0.5 32bits version on a machine as a windows service. In an admin console execute this command: netsh int tcp set global autotuninglevel=experimental After this, type command: netsh int tcp show Verify to have "Receive Window Auto-Tuning Level : experimental" Try to start mongo.exe client without any parameters, to connect to database. Mongo.exe will hang. You need to implement a timeout algorithm to close the client and to give an appropriate message if no connection can be made. I attached mongod.log and a capture file to see the packets sent.