If you've been feeling like you've been transported back to 2007 while using your computer these past few days, you're not alone. Microsoft accidentally replaced the Windows 11 preview build with the Windows Vista startup sound.
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Windows testers noticed the issue shortly after the release of the latest Dev Channel build of Windows 11 on Friday afternoon. The .WAV for the startup sound, which is located inside imageres.dll, had been accidentally replaced with the Windows Vista startup sound in the pre-release build 26200.5651.
Microsoft quickly acknowledged the error and added a note to the release notes. “This week’s test comes with a pleasant surprise from the past and will play the Windows Vista startup sound instead of the Windows 11 one,” the Windows Insider. “We’re working on a fix.”
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It's unclear how this error occurred, but Brandon LeBlanc from the Windows Insider team joked on X that "I went in and played around with the Windows sound files a little bit because I thought people needed a dose of nostalgia," before confirming that it was in fact a bug.

Perhaps one of the Windows engineers at Microsoft was feeling a little nostalgic for Windows Vista — especially in a week where the company hinted that it thinks Apple's new Liquid Glass design is a lot like Vista's Aero Glass
See also: Windows 11 24H2: Update triggers BSOD error
An interesting point about the above is that this incident highlighted how even small details, such as the startup sound, can evoke strong nostalgia or bring back memories of older versions of Windows. Windows Vista, despite its mixed reception when it was released, has now acquired an almost “retro” character, and for many users, such elements evoke feelings and memories of an earlier era of technology.
Source: theverge
