Microsoft quickly acknowledged the mistake in updated release notes for the Dev Channel build1. "This week's flight comes with a delightful blast from the past and will play the Windows Vista boot sound instead of the Windows 11 boot sound," the company stated1. "We're working on a fix."

Brandon LeBlanc, Senior Program Manager on the Windows Insider Program Team, initially joked on X that he "went in and had some fun with the sound files in Windows and thought folks needed a blast from the past"2. However, he later clarified that the audio swap was "an actual bug" rather than an intentional change2.

The error was first spotted by user XenoPanther on X, who discovered that the .WAV file for Windows 11's startup sound had been replaced with Windows Vista's audio file in the system's imageres.dll library12. The bug affected users who restarted their computers after installing the preview build released Friday3.

According to PC Mag, the sound change surprised users who had grown accustomed to Windows 11's modern audio cues3. The Vista startup sound, which was also used in Windows 7, became a familiar part of the computing experience for millions of users during the late 2000s2.

The bug's timing has sparked speculation in tech circles, arriving shortly after Apple unveiled its Liquid Glass design language at this year's Worldwide Developers Conference1. Critics have noted similarities between Apple's new visual approach and Windows Vista's Aero Glass interface from 20061.

While Microsoft has not explained how the audio files became mixed up, some observers wonder whether the "bug" might have originally been intended as a brief Easter egg1. The company recently posted on Instagram taking subtle shots at Apple over the design comparisons, though LeBlanc maintains the startup sound issue was unintentional1.