Which .NET Frameworks and Updates are Installed?

Recently we had to deal with an issue where a .NET Framework update caused a .NET 4.0 application to stop working. In fact the IIS worker process was crashing! Long story short, we had to figure out which versions of .NET and the respective updates were installed on the server in order to take corrective actions. The following links helped determine the information needed.

How to: Determine Which .NET Framework Versions Are Installed

How to: Determine Which .NET Framework Updates Are Installed