UuidCreateSequential

        [DllImport("rpcrt4.dll",SetLastError = true)]
        static extern int UuidCreateSequential(out Guid guid);

        static Guid UuidCreateSequential() {
            const int RPC_S_OK = 0;
            Guid g;
            int hr = UuidCreateSequential(out g);
            if(hr != RPC_S_OK)
                throw new ApplicationException
                  ("UuidCreateSequential failed: " + hr);
            return g;
        }