People often ask for the methods to fully clear the programming of their cash register so they can start again. This is especially so when they have purchased a second hand machine with previous owner's data still intact.
HOLD YOUR HORSES!
Many machines (especially the medium to high end registers) have a large amount of system configuration settings that you usually don't know about. A technician or programmer probably set many of those for your area/ taxes/ currency types etc. If you wipe these out, you may end up with a lot of screwing around and button pushing to find the right ones for you. It is far better just to modify the existing programming (item buttons, receipt message, staff settings etc). Hey don't we all like doing the minimum amount of work :-)
RAM (full memory) clearing is a last resort in most cases.
Note: This is not to be confused with resetting a report to show the days takings and ready the cash register for the next usage.
Please feel free to ask for advice. The answer may be simpler than you think.