Wow, that's old. That's an OS that was released in 1999. I wouldn't expect it to work in any capacity on the modern web, so just being able to use the internet until now is surprising. You shouldn't be using these machines for any publicly connected internet usage, as they are basically just open portals for anyone to attack.

I would suggest you immediately begin investigating upgrading to modern computers. Either Apple 10.10 or Windows 8.1