So the bios battery is dead. On a Windows XP machine in a workgroup enviroment the Windows time service simply does not work as it reports – “The computer did not resync because the required time change was too big.”
You can change it manually but every time the computer reboots it is going to set itself back to 2002.
You need to modify the registry to allow a bigger time change variation to be accepted from the Windows time service. This may not be ideal in a strictly controlled domain environment but in a small workgroup where an old machine is being used as a ‘server’ to share files it becomes essential that it is running on the correct time. If not backups will fail etc.
Look out for the keys MaxPosPhaseCorrection and MaxNegPhaseCorrection.
Set them to 0xFFFFFFFF to allow any change
restart the Windows time service
From command line run – w32tm /resync
The time will update correctly!