AES/DES question about determine a key
No. For any key $k$ your ciphertext $c$ has a corresponding plaintext $p$ (since block ciphers are families of bijections). Hence, since you can't (in)validate plaintexts, you can't discard any possible key.

Or, in other words: If someone claimed the right key was a certain $k$, you had absolutely no way to ever prove them wrong.