backintime-kde4: 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/backintime-kde4 - from package: backintime-kde

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

Error in other languages:
backintime-kde4: bevel nie gevind nie
backintime-kde4: comandă negăsită
backintime-kde4: comando não encontrado
backintime-kde4: commande introuvable
backintime-kde4: command not found
backintime-kde4: käsku ei ole
backintime-kde4: không tìm thấy lệnh
backintime-kde4: komanda nerasta
backintime-kde4: Kommando nicht gefunden.
backintime-kde4: kommandot finns inte
backintime-kde4: komut yok
backintime-kde4: nie znaleziono polecenia
backintime-kde4: níor aimsíodh an t-ordú
backintime-kde4: no se encontró la orden
backintime-kde4: no s'ha trobat l'ordre
backintime-kde4: opdracht niet gevonden
backintime-kde4: parancs nem található
backintime-kde4: perintah tidak ditemukan
backintime-kde4: príkaz nenájdený
backintime-kde4: příkaz nenalezen
backintime-kde4: команда не найдена
backintime-kde4: командата не е открита
backintime-kde4: 命令找不到
backintime-kde4: コマンドが見つかりません