The LM hash is hashed with the DES algorithm which has a block size of 64 bits (8 bytes), and key size 56 bits (7 bytes). That way if you double these two hashes you get a 14 byte hash. But naturally two 7 byte hashes is way weaker than one 14 byte hash.
The NT is more secure yes, its hashed with a MD4 algorithm, but still pretty fragile. MD4 hash size is 128 bits (16 bytes). MD4s limit is 2^64 bits, a lot. Windows password limit is 256 bytes, which equals 128 characters, also a lot. But dont get fooled, a 128 character password aint stronger than a 16 charter password, because of the hash size. You just got 8 equally weak hashes to handle instead of 1.
It depends on how many characters Cbecks password is then, but i dont think charcter lenght or hash type matters much when resetting. Those factors are important if you try to crack the password. Its resetting im talking about, no fishy activities involved, just to clear that out. Those tools should anyway be able to reset it.