The Critical Stop alert has been part of the default Windows sound scheme for many generations of the operating system, and the version most people recognise today is the Windows 7 recording. It was designed as a functional error sound for warnings that required the user to stop and read a dialogue box. As screen recordings and meme edits spread online, creators borrowed that familiar chime for fake crashes, blue screens and mock system messages, and its meaning transferred instantly to viewers who had heard it on their own PCs.