Also, you are not going to find any CD or ISO for a board that is almost 20 years old. Any software, such as PCGuardian, was shovelware, and not provided by any downloads on the Intel support site. Additionally, you board is discontinued, and long past any support.
Latest available BIOS can be downloaded here: https://downloadcenter.intel.com/download/3489/BIOS-Update-EA81510A-86A-?product=3317. These are the only forms available; no other forms will be provided.