RESOLUTION
Plesk 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, Plesk can be installed again..
WARNING: This article porvides the setps for complete Plesk reinstallation. ALL DATA will be lost in this case!!! Please do Full Plesk backup before in case it's necessary to save Plesk data.