Resolution
Parallels Plesk Panel can be uninstalled using Add/Remove Programs wizard or by running Plesk installer program and selecting the Uninstall option.The folders %plesk_dir% (usually C:\Program Files\SWsoft\Plesk) and %plesk_vhosts% (usually C:\Inetpub\vhosts) should be manually removed.
Once done, Parallels Plesk Panel can be installed again..
WARNING: This article provides the setps for complete Parallels Plesk Panel reinstallation. ALL DATA will be lost in this case!!! Please do Full Plesk backup before in case it's necessary to save Parallels Plesk Panel data.