Public launch of Microsoft 98 was failed. Bill Gates was demonstrating Windows 98 at Comdex computer industry trade show in Chicago. When one of employee was attempting to connect scanner to the successor of windows 95. Suddenly unexpected messages were being displayed on the screen and everyone in the room got to know that windows 98 has been crashed.
This is Blue Screen of Death. This what appeared on the screen after the crash of windows 98.
Crowd was able to see messages about crash on the big screens in the hall. Bill Gates had to change computer to complete his presentation. This happened due to lack of testing of the OS. All other companies learned from this incident and deployed additional resources to test softwares properly.