solid-hardware: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/solid-hardware - from package: kdebase-runtime

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/solid-hardware - from package: kde-runtime

You may install the required package with command apt-get install {package}

Error in other languages:
solid-hardware: bevel nie gevind nie
solid-hardware: comandă negăsită
solid-hardware: comando não encontrado
solid-hardware: commande introuvable
solid-hardware: command not found
solid-hardware: käsku ei ole
solid-hardware: không tìm thấy lệnh
solid-hardware: komanda nerasta
solid-hardware: Kommando nicht gefunden.
solid-hardware: kommandot finns inte
solid-hardware: komut yok
solid-hardware: nie znaleziono polecenia
solid-hardware: níor aimsíodh an t-ordú
solid-hardware: no se encontró la orden
solid-hardware: no s'ha trobat l'ordre
solid-hardware: opdracht niet gevonden
solid-hardware: parancs nem található
solid-hardware: perintah tidak ditemukan
solid-hardware: príkaz nenájdený
solid-hardware: příkaz nenalezen
solid-hardware: команда не найдена
solid-hardware: командата не е открита
solid-hardware: 命令找不到
solid-hardware: コマンドが見つかりません