A developer searching for old GUI applications that still run unmodified on Windows 11 launched CDPLAYER.EXE from a November 1992 build. Its use of a system C runtime still present today avoided compatibility problems affecting other early NT applications. Demonstrating audio playback nevertheless required a separate DLL that simulated a CD-ROM drive. A 1993 FreeCell build remained directly playable, while 1985 Reversi ran through otvdm emulation. These are findings from an individual experiment, not proof of universal old-app support or an absolute oldest-ever record.