Go here
http://www.tek-tips.com/viewthread.cfm?qid=362041 , read terms of use , make a module and after do this:
Make a table Log with fields NetBios,IP,Data,Hour
In that form who opens when your database open (FOpen for example) make
2 text with Visible = NO txthost and txtip
Make an event On Open or On Load and put this
[Forms]![FOpen]![txthost] = GetIPHostName()
[Forms]![FOpen]![txtip] = GetIPAddress()
Dim rst As Recordset, sqlstmt As String
Set dbs = CurrentDb
sqlstmt = "Log"
Set rst = dbs.OpenRecordset(sqlstmt, dbOpenDynaset)
rst.AddNew
rst![NetBios] = Me!txthost
rst![IP] = Me!txtip
rst![Data] = Date
rst![Hour] = Time()
rst.Update
rst.Close