Asp.net password history

There is nothing built into .Net that will provide this information. You would have to write your own solution to create an audit trail of passwords but this would involve storing passwords

In fact, storing plain passwords is the worst approach in terms of security.

Administrator must not have access to plain passwords, this the reason of most of applications prompts you to create a new one, because passwords are hashed and hashing prevents from reverting to plain text.

If you need to track passwords, you'll need to write a custom membership provider tracking them.