Alex smiled. It wasn't magic—it was just knowing exactly which version of a twenty-year-old framework was holding the whole system together. He went back to his desk and made a note in the company wiki: Always keep a copy of netfx20sp1_upd in the 'Emergency' folder.
update. This package provides cumulative updates, security improvements, and prerequisite support for newer versions like .NET 3.0 SP1 and .NET 3.5. Key Details netfx20sp1 upd