I re-wrote this, because even after "fixing" it for you I'm not sure it gave you the data you wanted. Is this what you're looking for?
Select
Evt_AeX_Client_LogOn.[User],
Evt_AeX_Client_LogOn.Event,
Evt_AeX_Client_LogOn._eventTime,
Inv_AeX_AC_Identification.Name
From
Evt_AeX_Client_LogOn Inner Join
Inv_AeX_AC_Identification On Evt_AeX_Client_LogOn._ResourceGuid = Inv_AeX_AC_Identification._ResourceGuid
Where
Evt_AeX_Client_LogOn._eventTime Between GetDate() - 30 And GetDate()
Group By
Evt_AeX_Client_LogOn.[User], Evt_AeX_Client_LogOn._eventTime, Evt_AeX_Client_LogOn.Event, Inv_AeX_AC_Identification.Name
Order By
Evt_AeX_Client_LogOn.[User], Evt_AeX_Client_LogOn._eventTime