This is the most common "working" driver for 64-bit systems. You can find legacy versions through the HPE Support Center .
2024-05-24 (Updated for current relevance) Subject: Feasibility and Procedure for installing ATI ES1000 (RN50) drivers on Microsoft Windows Server 2016. Target Environment: Legacy servers (e.g., Dell PowerEdge 1950/2950, HP ProLiant DL380 G5) or industrial embedded systems. Ati Es1000 Driver Windows Server 2016