You can find drivers for this card through several reputable third-party archives and legacy support pages:

The is an older graphics card based on the ATI Radeon X600 PRO chip. Since the card is a legacy product, official support from ASUS and AMD has largely transitioned to archives. Driver Download Options

: Offers a package containing the ASUS EAX600 PRO for Windows developed by Advanced Micro Devices (ATI).