You can set the 'session timeout' value by going to Site Administration / Server / Session Handling. The default setting is 2 hours.
thanks for your reply
i did found it already 2 hours while exam was only 30 minutes, i made it anyway 4 hours, but is it sure that this is the cause of the problem as we can not take the adventure in the next exams
now i tried with an account, the problem still exist, account logged out after about 1 hour so i think it comes from password expiration feature
is there is a way to make password expiration after more than 1 hour?