Installation IE 7 impossible [Résolu]

Bonjour,
Je n'arrive désespérément pas à télécharger internet explorer 7.
J'ai fait quelques recherches et rien ne marche :
* désactivation de tout système de sécurité (avast et zonealarm)
* taper dans exécuter : secedit /configure /cfg %windir%\repair\secsetup.inf /db secsetup.sdb /areas REGKEYS
(il me met que Windows n'a pas trouvé secedit).
* Modifier dans le registre .application les droits (je n'ai qu'une seule session donc forcément j'ai tous les droits).
* Mon Windows XP est bien évidemment légal.
Voici le rapport IE.log si ça peut servir :
3.937: IECUSTOM: Finished setting new registry permissions...
3.937: IECUSTOM: An error occured verifying registry permissions. ERROR: 0x80070534
3.937: DoInstallation: CustomizeCall Failed: 0x3f5
3.968: IECUSTOM: Restoring registry permissions...
3.984: IECUSTOM: Finished restoring registry permissions...
4.015: Impossible d'écrire la clé du Registre de configuration.
4.031: L'installation du Internet Explorer 7 ne s'est pas terminée.
4.031: Update.exe extended error code = 0x3f5
0.641: ================================================================================
0.656: 2008/08/26 23:59:58.500 (local)
0.656: c:\aaf88abc8557342205d691\update\update.exe (version 6.2.29.0)
0.734: Hotfix started with following command line: /quiet /norestart /er /log:C:\WINDOWS
0.781: IECUSTOM: Scanning for proper registry permissions...
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\ProxyStubClsid
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\ProxyStubClsid32
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\TypeLib
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\TypeLib
1.859: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
2.969: IECUSTOM: Scanning for proper registry permissions...
3.328: IECUSTOM: Scanning for proper registry permissions...
3.922: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
4.125: IECUSTOM: Backing up registry permissions...
4.313: IECUSTOM: Finished backing up registry permissions...
4.313: IECUSTOM: Setting new registry permissions...
4.328: IECUSTOM: Unable to clear DACLs HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
4.328: IECUSTOM: Finished setting new registry permissions...
4.328: IECUSTOM: An error occured verifying registry permissions. ERROR: 0x80070534
4.328: DoInstallation: CustomizeCall Failed: 0x3f5
4.328: IECUSTOM: Restoring registry permissions...
4.359: IECUSTOM: Finished restoring registry permissions...
4.375: Impossible d'écrire la clé du Registre de configuration.
4.406: L'installation du Internet Explorer 7 ne s'est pas terminée.
4.406: Update.exe extended error code = 0x3f5
0.875: ================================================================================
0.891: 2008/08/27 00:23:34.765 (local)
0.906: c:\4431182d8776b886312e6bf33b\update\update.exe (version 6.2.29.0)
1.031: Hotfix started with following command line: /quiet /norestart /er /log:C:\WINDOWS
1.031: IECUSTOM: Scanning for proper registry permissions...
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\ProxyStubClsid
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\ProxyStubClsid32
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\TypeLib
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}\TypeLib
2.047: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
3.062: IECUSTOM: Scanning for proper registry permissions...
3.375: IECUSTOM: Scanning for proper registry permissions...
3.891: IECUSTOM: Unwriteable key HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
4.094: IECUSTOM: Backing up registry permissions...
4.172: IECUSTOM: Finished backing up registry permissions...
4.172: IECUSTOM: Setting new registry permissions...
4.219: IECUSTOM: Unable to clear DACLs HKCR\Interface\{34A715A0-6587-11D0-924A-0020AFC7AC4D}
4.219: IECUSTOM: Finished setting new registry permissions...
4.219: IECUSTOM: An error occured verifying registry permissions. ERROR: 0x80070534
4.219: DoInstallation: CustomizeCall Failed: 0x3f5
4.234: IECUSTOM: Restoring registry permissions...
4.250: IECUSTOM: Finished restoring registry permissions...
4.266: Impossible d'écrire la clé du Registre de configuration.
4.266: L'installation du Internet Explorer 7 ne s'est pas terminée.
4.266: Update.exe extended error code = 0x3f5
Merci.