Hi Lorraine-
I'm assuming you have a high-end Sam4s register like the SER-7000/7040 or SPS-500/1000/2000. In order to access the system password on the SER-7000, SPS-500 or SPS-1000, you will need a service key - a key with a 'C' stamped on it. If you don't have a service key, see my response to "how do I clear memory on sam4s?" further down this category for your options. If you have a service key, turn the keyswitch to the S position (one click clockwise past the P position). On the S-Mode menu there will be a "SYSTEM PASSWORD" option. If you select that, it will display the current system password for you. To disable the system password, change it to '0000' (four zeros).
If you have an SPS-2000, it's a bit more complicated. If that's the case, post again and I'll try to help further.
Steve, August 2010