Ideally you would have generated and saved a HASH before you copied your files as a control. Otherwise, it’s just a probability game. If the HASH on copy 1&2 match, but doesn’t match 3, then the probability is 1&2 are correct. If all three don’t match, you toss a coin.
If you’re on Windows, I recommend using Teracopy for all your file copying (always copy, never move!) and set verify on, which will perform a CRC and generate a HASH which you can then save. You can also use it to Test your files after the fact and generate a HASH.
Ideally you would have generated and saved a HASH before you copied your files as a control. Otherwise, it’s just a probability game. If the HASH on copy 1&2 match, but doesn’t match 3, then the probability is 1&2 are correct. If all three don’t match, you toss a coin.
If you’re on Windows, I recommend using Teracopy for all your file copying (always copy, never move!) and set verify on, which will perform a CRC and generate a HASH which you can then save. You can also use it to Test your files after the fact and generate a HASH.