qtconfig: 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/lib64/qt-3.3/bin/qtconfig - from package: qt3-config
/usr/lib64/qt4/bin/qtconfig - from package: qt-x11
/usr/lib/qt4/bin/qtconfig - from package: qt-x11

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

On Debian possible default full paths are:

/usr/lib/x86_64-linux-gnu/qt4/bin/qtconfig - from package: qt4-qtconfig
/usr/bin/qtconfig - from package: qtchooser

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

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