Whistler was Microsoft's codename for Windows XP during its 2000 to 2001 development, between Windows 2000 and ME. Clips labeled as the Whistler chord circulate on soundboards as a startup chime, though many uploads are also tagged as a Windows 98, 2000 or ME error sound. The confusion helped it spread, with meme editors reusing it for fake crashes, retro PC parodies and vaporwave edits on YouTube and TikTok. It endures because that early-2000s startup audio instantly signals outdated tech.