No error code to write down, hehe. Literally all of them look like this one. :lol:
Is the battery necessary? Removing the dead one is on my list of things to do, but unless their absence will cause a problem I'm generally not a fan of using batteries since they can be bad for the environment. I'm not sure I have the System CD or if it's all on floppies, but I think I still have them somewhere. Maybe Disk First Aid is on them.