New AGP Card won’t Work

Hi,

I have a Celeron 300MHz of 1998. Recently I bought an AGP Card to replace the one in it. But when I installed it, it won’t work. I checked the AGP card. It is alright and works when installed in another system. I have no reason to suspect that the slot is bad. Then what could be the reason? Is my old AGP slot obselete and has to be upgraded ? Is it something like that? Do new AGP cards work with old AGP slots?