IDS admin user name and password not recognize

Hello, I have IDS development version 11.7 running on Windows 7 as a window service, it's been running for a while without issue, then all of sudden I'm unable to connect to server, error message states that user name is not known on the database server. User name/password was established during the installation proces and has not changed and user is a member informix-admin group. Nothing in log file, or event log. Any help would be greatly appreciated.

How are you trying to connect? For example does dbaccess connect, dies onst= at? Can you logon to the machine as the Informix user? Can you change the w= indows service to run as the localsystem user?=