We STILL don't know because you have not listed the motherboard make and model. You put:
AMD SOCKET A motherboard VIA KT266A ATX
There are a LOT of socket A motherboards and a LOT of motherboards that nse the VIA KT266A chipset.
Until we know that we cannot begin to help. If you don't know and you don't have it ona receipt you will just have to LOOK at the thing. It will be printed on the motherboard.