pop-tkdesk: 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 Debian possible default full paths are:

/usr/bin/pop-tkdesk - from package: tkdesk

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

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