Ok,well it could be that your cd reader has packed up as it is an old machine ,several ways to do this but as this machine is regarded as a project machine ....I would suggest you try a live cd like Ubuntu to verify if it is reading and if it is and system is working I might suggest that you install it or another live cd from Linux as they are more advanced than windows ,especially 98 and will work on older machines better than newer ones.
good luck and PM
me if you need help with installation or package help,etc.