Is this PInvoke code correct and reliable?

In this question I have searched for a simple solution to unblock files. Thanks to all the comments and answer, I have found a simple solution by PInvoking DeleteFile.

It works, but because I've never used file-operations through PInvoke (Win32), I don't know if there are some pitfalls or if there is another method of calling DeleteFile to delete the alternate stream of a file.

What I also don't know is if I have to wrap the call in a try/catch or if it is enough just to look the at the boolean result. In my tests, no exceptions were raised, but I don't know what will happen in the real world.

public class FileUnblocker {

    [DllImport("kernel32", CharSet = CharSet.Unicode, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool DeleteFile(string name );

    public bool Unblock(string fileName) {
        return DeleteFile(fileName+ ":Zone.Identifier");
    }
}

Does this code look reliable?

Update
I had posted an incomplete method (the unblock method didn't concatenate the "Zone.Identifier" literal to the file name). I have corrected this now, sorry.