On this MSDN page the CredWriteW function is described and there is a section of the errors it can return if it does not complete successfully. However I do not see what number/integer each error code corresponds to. Since if the function returns FALSE we must use GetLastError to get the status code, which is a number, then how can I map the status code to one of the error codes shown in the MSDN page?

I am not sure if the FormatMessage function will help, as I am not sure if CredWriteW is a “system” function.

So, what I want to know is, for example, which status code/number does ERROR_INVALID_FLAGS correspond to?

When I run my code and CredWriteW returns false and I get some number from GetLastError what does that number mean?

I am using C# and LibraryImport.