Q:

Handle Win32Exception thrown by Process. Start()

On some computers, when I call Process. Start() to start my helper executable, I get the following exception:
System. ComponentModel. Win32Exception (0x80004005): The system cannot find the file specified
at System. Diagnostics. Process. StartWithCreateProcess(ProcessStartInfo startInfo)
at System. Diagnostics. Process. Start()

The question: when I get Win32Exception, I want to tell if this is the "file not found" exception I described or something else.  How to do this reliably?  Should I compare this 0x80004005 against something, or should I parse the error message? 
Some explanation: the executable may get removed by for some reason (that's why file not found).  This is an expected situation.  If the exception was thrown with some other reason, I want to report it. 

A:

This is how, I believe, it should be done:
public static int E_FAIL = unchecked((int)0x80004005);
public static int ERROR_FILE_NOT_FOUND = 0x2;

// When the exception is caught

catch (Win32Exception e)
{
    if(e. ErrorCode == E_FAIL && e.NativeErrorCode == ERROR_FILE_NOT_FOUND)
    {
    // This is a "File not found" exception
    }
    else
    {
    // This is something else
    }
}

E_FAIL is a HRESULT value, ERROR_FILE_NOT_FOUND is a system error code. 
The error message shouldn't be used because it is culture-dependent and is actually a translation of the system error code.