ppdhtml: 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/ppdhtml - from package: cups

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

On Debian possible default full paths are:

/usr/bin/ppdhtml - from package: cups-ppdc

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

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