wvdialconf: 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/wvdialconf - from package: wvdial

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

On Debian possible default full paths are:

/usr/bin/wvdialconf - from package: wvdial

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

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