gdebi-kde: command not found

Have You tried accessing the binary with the full path?

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/gdebi-kde - from package: gdebi-kde

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