Hi.
You may not need one if you are only changing basic details. The P key may be all you need. If you check the manual, it should tell you what functions require the C key. Deep functions like memory allocation and keyboard layout change require the C key and you don't normally need to set these up unless data has been lost. If the machine has been sitting longer than 2 months, the battery will be flat and you will absolutely need a C key, or it would be best to take it to a dealer in that case.
Mark, September 2009
