To protect the security of your Miva Merchant online store, Miva Corporation does not have any access to passwords for the many installations of Miva Merchant. Your username and password are created when you initially setup Miva Merchant on your domain. The password is encrypted and stored in a database on the server. To “RESET” the password with only the Miva Merchant software that we provide, you would have to reinstall and start from scratch. We can do this for you for free.
There is another option, though:

Miva Corporation has many 3rd party developers. Some of these developers offer this type of service for a nominal fee. To find a list of Miva Corporation, Development Partners please see the Partner Area:

Please feel free to open a support ticket from your MyCP if you have any questions about this.