My computer is not v old and I noticed the other day that the system clock was "out" by about 4 mins. Speaking with some friends who are more 'puter literate than I, I was told that anti-virus software or system optimising software can make the clock run slow - the 'puter regards the clock as less important hence the going slow. To avoid this, there is a great website
http://worldtimeserver.com from where you can download a program that lets you "ping" an Atomic Clock to update your system clock! It really is great. Of course, if you have a 'puter that is more than 8yrs old then it is also possible that your system battery needs replacing and that is a whole new ballgame (if/when I get to that point I will be asking for help on how to to it!!).
HTH (hope this helps).
