You can login into the server through SSH and the issue the following command at the prompt.
[root@localhost ~]# cat /etc/psa/.psa.shadow
The easiest way to recover the admin password on a Windows server with a Plesk installation is accessed by a shell or terminal server and run this command.
C:\>”%plesk_bin%”\plesksrvclient.exe -get
the window wont open with the Plesk admin password.
If you require help, contact SupportPRO Server Admin