Problem: I tried everything in bluetooth places, it showed “device not detected”. I checked drivers in system device management, but it showed everything worked ok. I used PC doctor, no error found. I checked system “Services”. The bluetooth service was running perfectly.
Solution: Very simple! Actually, in thinkpad x61t, open ThinkVantage Access Connections, there’s an option to turn on/off bluetooth device. I turned it off sometime before and forgot.