I'm not sure that the latest Nvidia drivers are too good with this card. Leadtek drivers are out of date? What driver should I be using?

Half Life is crashing with this error..NVARCH16.DLL?

The NV drivers seem a little too harsh on my display, desktop wise (sync).

Sys spec:
Abit KT7A+ Mobo
Duron 750Mhz (o/c to 950Mhz)
Global Win Fop32 Heatsink & Cooler
3 x 128Mb Ram (2@100, 1@133)
IBM 14.2 Gb Udma 66 Ide
Leadtek Winfast GeForce 256 ddr Agp
ATI Tv Wonder Pci
Panasonic 24x8x4 Cd Rw Ide
Hitachi G5000 Dvd Ide
Win 98 se