Problème d'instal

Bonjour,

Ce week end, j'ai voulu installer un cours de langue sur mon ordi (vista - firefox).... impossible d'installer : message d'erreur

%% PLEASE DO NOT MODIFY OR DELETE THIS FILE! %%
%% This file contains information about the installation of an application. %%
%% It will be used to automatically remove all application components from your computer if you choose to do so. %%

NOTE: Beginning of the bootstrapper section

*** ERROR: Unable to create a directory named 'C:'
*** DURING THIS ACTION: CreateDir: "C:"

CONFIG: Title: "Idiomas Taalcursus Nederlands-Frans"

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion", "SharedDLLs"

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\VB6STKIT.DLL"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\COMCAT.DLL"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\MSWINSCK.OCX"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\MSMAPI32.OCX"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\STDOLE2.TLB"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\ASYCFILT.DLL"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\OLEPRO32.DLL"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\OLEAUT32.DLL"
(File currently on disk was already up to date)

ACTION: SystemFile: "C:\WINDOWS\SYSTEM32\msvbvm60.dll"
(File currently on disk was already up to date)

ACTION: DllSelfRegister: "C:\WINDOWS\SYSTEM32\COMCAT.DLL"

ACTION: DllSelfRegister: "C:\WINDOWS\SYSTEM32\MSWINSCK.OCX"

ACTION: DllSelfRegister: "C:\WINDOWS\SYSTEM32\MSMAPI32.OCX"

ACTION: TLBRegister: "C:\WINDOWS\SYSTEM32\STDOLE2.TLB"

ACTION: DllSelfRegister: "C:\WINDOWS\SYSTEM32\OLEPRO32.DLL"

ACTION: DllSelfRegister: "C:\WINDOWS\SYSTEM32\OLEAUT32.DLL"

ACTION: DllSelfRegister: "C:\WINDOWS\SYSTEM32\msvbvm60.dll"

NOTE: End of the bootstrapper section

NOTE: Now spawning the main Setup program 'Setup1.exe'....

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE", "Idiomas\TaalCursus\FR_NL"

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE", "Idiomas\TaalCursus\FR_NL"

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE", "Idiomas\TaalCursus\FR_NL"

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE", "Idiomas\TaalCursus\FR_NL"

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE", "Idiomas\TaalCursus\FR_NL"

ACTION: RegKey: "HKEY_LOCAL_MACHINE\SOFTWARE", "Idiomas\TaalCursus\FR_NL"

*** ERROR: Setup1::buildcode_0004h => 6: Overflow
*** ERROR: Oeps... De fout die nu is opgetreden kan niet verklaard worden!
*** ERROR: Kijk eens in ST6UNST.??? of IDIOMAS_SETUP.INI in de 'Windows' folder, misschien bevatten die files een verklaring.
*** ERROR: (User Responded with 'Opnieuw')

*** ERROR: Setup1::buildcode_0004h => 6: Overflow
*** ERROR: Oeps... De fout die nu is opgetreden kan niet verklaard worden!
*** ERROR: Kijk eens in ST6UNST.??? of IDIOMAS_SETUP.INI in de 'Windows' folder, misschien bevatten die files een verklaring.
*** ERROR: (User Responded with 'Annuleren')

*** WARNING: Ik was nog niet klaar!
*** WARNING: Zeg eens... als u nu stopt dan is dit programma niet volledig geïnstalleerd.
*** WARNING: Wilt u de setup verlaten?
*** WARNING: (User Responded with 'Ja')

*** WARNING: Ja lap! Idiomas Taalcursus Nederlands-Frans Setup was onderbroken vóór de installatie van het programma volledig gedaan was.
*** WARNING: U moet Idiomas Taalcursus Nederlands-Frans Setup opnieuw volledig uitvoeren vooraleer het programma kan gebruikt worden.
*** WARNING: (User Responded with 'Oké')

Quelqu'un pourrait-il me dire ce que je pourrais faire pour corriger tout ça?
merci

--
"Mieux vaut prévenir que guérir..."