Probléme de chargement de course

Bonjour
J'ai acheté le jeu via la plateforme STEAM.
Lorsque je lance une course, le jeu charge les routes, décors et autres puis fini toujours par se bloquer.
Ma configuration :
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System Information
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Time of this report: 7/3/2015, 17:55:51
Operating System: Windows 7 Édition Familiale Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.110408-1631)
System Manufacturer: ASUSTeK Computer Inc.
System Model: N71Ja
BIOS: BIOS Date: 10/30/09 15:13:23 Ver: 08.00.10
Processor: Intel(R) Core(TM) i5 CPU M 430 @ 2.27GHz (4 CPUs), ~2.3GHz
Memory: 4096MB RAM
Available OS Memory: 3948MB RAM
Page File: 4045MB used, 3850MB availab
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7601.17514 32bit Unicode

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DxDiag Notes
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Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Sound Tab 2: No problems found.
Input Tab: No problems found.

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DirectX Debug Levels
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Direct3D: 0/4 (retail)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (retail)
DirectMusic: 0/5 (retail)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)

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Display Devices
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Card name: ATI Mobility Radeon HD 5730
Manufacturer: ATI Technologies Inc.
Chip type: ATI display adapter (0x68C0)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_68C0&SUBSYS_1C221043&REV_00
Display Memory: 2732 MB
Dedicated Memory: 1014 MB
Shared Memory: 1718 MB
Current Mode: 1600 x 900 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: unknown
Monitor Id: LGD01DD
Native Mode: 1600 x 900(p) (60.080Hz)
Output Type: Internal
Driver Name: atiumd64.dll,atidxx64.dll,atidxx64.dll,atiumdag,atidxx32,atidxx32,atiumdva,atiumd6a.cap,atitmm64.dll
Driver File Version: 8.14.0010.0716 (English)
Driver Version: 8.680.0.0
DDI Version: 11
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 11/18/2009 07:18:19, 4675584 bytes
WHQL Logo'd: Yes
WHQL Date Stamp:
Device Identifier: {D7B71EE2-2B80-11CF-3F71-283CA1C2C535}
Vendor ID: 0x1002
Device ID: 0x68C0
SubSys ID: 0x1C221043
Revision ID: 0x0000
Driver Strong Name: oem9.inf:ATI.Mfg.NTamd64.6.1:ati2mtag_Manhattan:8.680.0.0:pci\ven_1002&dev_68c0&subsys_1c221043
Rank Of Driver: 00E60001
Video Accel: ModeMPEG2_A ModeMPEG2_C
Deinterlace Caps: {6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY
{6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YV12,0x32315659) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{3C5323C1-6FB7-44F5-9081-056BF2EE449D}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{552C0DAD-CCBC-420B-83C8-74943CF9F1A6}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC1,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC2,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC3,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC4,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(S340,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(S342,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
D3D9 Overlay: Not Supported
DXVA-HD: Not Supported
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled

Pouvez vous m'aider ?

Merci d'avance

Je peux jouer sur la piste en mode graphique haut.

[FocusTechSupport]

Display Devices
Card name: ATI Mobility Radeon HD 5730
Driver Date/Size: 11/18/2009 07:18:19, 4675584 bytes

Veuillez mettre à jour les pilotes de la carte graphique ATI Mobility Radeon HD 5730 :

1. Cliquer http://support.amd.com/fr-fr/download
2. Cliquer le bouton 'TELECHARGEZ MAINTENANT' en dessous de Détecter et installer automatiquement le pilote.
3. Télécharger et exécuter l'application 'autodetectutility.exe'.
4. Si une mise à jour est disponible, cliquer le bouton 'DOWNLOAD NOW'.
5. Une fois le téléchargement terminé, cliquer le bouton 'Install' depuis le programme d'installation AMD Catalyst Software.
6. Cliquer le bouton 'Suivant'.
7. Cocher 'Personnalisé' en dessous de 'Bienvenue' et cliquer le bouton 'Suivant'.
8. Décocher 'AMD Quick Stream Technology' et 'AMD Gaming Evolved App' (si disponibles) en dessous de 'Sélection du composant'.
9. Cliquer le bouton 'Suivant' puis le bouton 'Accepter'.