Clearing my Network settings

How do i clear all of my network settings to defaults settings without doing a hard reset and losing all of my data. Reason for why i need it to be reset is whenever i dock my x51 axim and have activesync loaded it keeps asking for a username/password/domain. Will be nice to clear all of my network settings so i dont get this message

Even when i delete all of the network settings, i still get that message