The installation steps for PC based systems are different compared to other platforms (RPI, Tinkerboard)
Follow these steps to install Volumio on your PC.
Remember that Volumio is a stand-alone OS, all the HDD contents will be overwritten.
Flash the x86/x64 IMG, you find here, on a USB KEY using Balena Etcher software
Insert the USB KEY in the USB port of the PC
Boot the PC from the USB KEY
It will start the Volumio First Config Wizard
Once done, Go to SETTINGS-->SYSTEM-->INSTALL TO DISK, you will transfer the OS from the USB KEY to the internal HDD
From now everytime you boot the PC from the default unit, Volumio will start as first OS
Please note: it is possible to boot Volumio everytime from USB KEY, but the performances will substantially decrease