replace the system battery. These are available from Radio Shack. You will find it on the logic board laying inside a little black plastic coffin.
If it continues to forget things, it may be a corrupt system.
If that is the case, insert the 10.2 installer CD and boot the machine from it. As the installer progresses, you will be asked what type of install you want to do. Choose Archive and Install. This will replace your system folder with a new one and keep all your data and setting intact.
If you wish to format the drive/partition, you will need to save the stuff you have in the Users/yourname folder.
Do not save applications, just data you have created. Music/pictures/docs etc.
Try the battery first
P
I`ve been having problems with my computer "forgetting" things....color settings, homepage settings, etc. My local Mac place told me it sounds like the software has become corrupt and that I should reinstall the OS...okay, I can do that.
My question is: what do I need to back up? I really don`t want to have to chase down installers and passwords to replace all the stuff on all the partitions if I don`t have to. Should I reformat the whole drive (currently three partitions) or just erase the partition with the system software?
I`m running OS 10.2.8 on an AGP G4 with 768 mb RAM and 1GHz G4 processor upgrade (done around a year ago).

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic