Agree, Thinkpad 600 is a laptop - get the full spec from the base and go to the 'lenovo' site. The codes and manuals are all there. Not sure, but I think you may have a back up problem or is it 'clock set', can't remember. I guess your machine is about 5 years old and a new back-up battery is required. It's a coin size thing under the RAM panel - look for red and black wires coming from a small white plug. You can also get the part number and order online. They will also give you the procedure for restarting from this alarm.....Print off most of the manuals while you are there, it will be handy in the future.....
Malcolm X
October 2007