Optiplex G1 can't detect ISA legacy slot

Hi

So i inherited a computer at work and i had to format the HD and install windows 2000 (which was there before). Unfortunately now it can no longer recognize ISA slots nor the ISA card on it before, even after I installed the driver (called driverLINX). I found this help page: http://www.axon.com/pages/mdc_kb_article.cfm?ArticleID=605 For this card that tells me how to reserve IRQs for Legacy ISA. Unfortunately the bios won't let me change from pnp to isa/legacy. Is there a driver i can download to solve this problem or something? I really need your help

Model G1 (or Gx1)

Celeron chip