You can install the OS by yourself on the VPS Management Page at the Manage tab.

Linux server username is the root and the password has to be set up by yourself on your VPS Management page.
Windows server (Windows 2003, 2008, 2019, 2022) username is Administrator and the default password is Plian8tua
Windows server (Windows 2012, 2016) username is Administrator and the default password is Plian>8tua
Windows Home (Windows XP. Windows 7, Windows 10) username is Admin and the default password is Plian8tua

Linux/Windows KVM, in case you forgot your password and has to be reset at VPS Management >> Advance Control Panel >> Open Control Panel >> login https://vcp.paidooserver.com >> manage >> Root/Admin Password.