.NET Runtime 2.0 Error on .NET 3.5 application

My colleagues and I have some misunderstandings about the .NET runtime. I've written a WPF application (targeted for 3.5) that randomly crashes, and in the event log, we see .NET Runtime 2.0 Error Reporting as the source.

Just to confirm:

• 3.5 still runs on the .NET 2.0 Runtime (i.e., it's an extension of it), so an application targeting 3.5 will still show .开发者_StackOverflow社区NET Runtime 2.0 as it's error source.
• When installing .NET 3.5 Framework, there's no way to not install .NET 2.0 along with it.

Am I right?

You are correct. There are, currently, 4 .NET runtimes (though the last is in beta).

1. 1.0 Runtime, which was very buggy
2. 1.1 Runtime
3. 2.0 Runtime, which is used for .NET 2.0, 3.0, 3.5, and 3.5sp1, as well as Silverlight
4. 4.0 Runtime - In Beta2, and soon to be released with VS 2010 and will be used by .NET 4.0

There is no way to install .NET 3.5 without the 2.0 runtime, since it uses that runtime, and is based on it.

You are correct on both points.

Yes, you are right. The .NET 3.5 Framework runs on .NET 2.0 CLR. Essentially the change is new assemblies (and new versions of .NET 2.0 assemblies) and new compilers.