>>From these two statements which seem to agree with each other I can conclude the following: No one created an exe and tested on a clean machine until the last day or two.
>
>Disclaimer: I'm speculating here.
>
>Or the bug got introduced very late in the game while fixing something else, or no beta tester tried deployment with the particular version in question.
>
>Tamar

Think I will speculate also.
1. SQA did not do their job. I do not know if a SQA team is used for this purpose by Microsoft.
2. A test plan is used by some companies to test software to specific requirements. This requirement may not have been defined.

If only "Beta" testers are used, what test methodology is used? Anything formal or whatever the Beta tester chooses to do?

Tom