Application Verifier provides fault injection, as well as detection for a bunch of conditions (https://learn.microsoft.com/en-us/windows-hardware/drivers/d...).

It's only intended for native/unmanaged code though.

The recommended approach for managed apps (meaning .NET) is probably dependency injection. If you want to test a component with fallible methods, write an interface wrapper and inject a fallible mock. The JIT will do dynamic PGO and devirtualize in normal application usage.

Dtrace can do the same and much more I believe with destructive actions, and it is supported on Windows.

And OpenBSD? :D