regpatch: 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/regpatch - from package: samba4-client

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

On Debian possible default full paths are:

/usr/bin/regpatch - from package: registry-tools

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

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