Hijacking the top comment in hopes of clearing up the confusion since this happens every year around this time (in alignment with the anniversary of the RTM date of August 24th).
This footage is often misrepresented as footage from the Windows 95 launch party. This was in fact a Windows 95 marketing event with the execs present, but the actual employee launch party featured Jay Leno with a completely different stage.
Read more about it on Raymond Chen’s (a legendary Windows SDE) post on the official Microsoft Blog.
https://devblogs.microsoft.com/oldnewthing/20170824-00/?p=96885
Source: Outside of what I linked below, I started on the Windows team at Microsoft in the late 90s shortly after all this took place. I was there for the Windows 2000 launch party. Here are a few pics that I have saved from it. It had to be moved to the parking garage under building 26 due to some bad weather if I remember correctly. To be honest though, I don’t really remember much from that day, or week even. Far too much alcohol was consumed in all the celebrations. It’s a VERY different company today.