%USERPROFILE%\Documents\Battle Chess\savegame.dat (Back this up before reinstalling.)
The game is designed to run on a wide range of hardware, as detailed on PCGamingWiki Minimum Requirement Recommended Windows XP, 7, 8 Windows 7, 8 1.0 GHz or faster 1.4 GHz or faster 750 MB RAM 3 GB available space 3 GB available space DirectX 9.0c compatible 3D Graphics card for certain pieces or the history of the original 1988 version Battle Chess: Game of Kings™ on Steam Battle Chess Game of Kings v1.1.1.18720