Unreal Engine 4.8 fatal error at startup

I want to start making games with Unreal Engine 4. So, I downloaded a pre-compiled version of UE4 from a reliable third-party website, which is worked for my friend.
For running UE4, I start UE4editor.exe from C:\UE4\Engine\Binaries\Win64 folder.
When I run it, the following error message shows, the progress hangs on 0% and quits.

Also, notice the address mentioned in error message: D:\Unreal Engine 4.8.0 NV-Techs... which is not correct! As I said before, my UE4 folder is C:\UE4. Whats wrong?!!

What can I do to solve the problem?!!
I attached log and dump files. If any other details needed please tell me.
Thanks for your attention

system specs:

• Windows 8.1
• CPU: Core i5
• RAM: 4GB
• GPU: AMD Radeon 6300M series

Log files:
UE4 logs.rar

error message:

 ---------------------------
 The UE4- Editor has crashed and will close
 ---------------------------
 Fatal error: [File:D:\Unreal Engine 4.8.0 NV-Techs\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Util.cpp] [Line: 223] 
 Direct3DDevice->CreateTexture2D(TextureDesc,SubResourceData,OutTexture2D) failed 
  at D:\Unreal Engine 4.8.0 NV-Techs\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Texture.cpp:458 
  with error E_INVALIDARG, 
  Size=512x512x1 Format=(0x00000035), NumMips=1, Flags=D3D11_BIND_DEPTH_STENCIL D3D11_BIND_SHADER_RESOURCE 

 KERNELBASE.dll {0x00007ffce1d58b9c} + 0 bytes

 UE4Editor-Core.dll {0x00007ffccc08087f} + 0 bytes

 UE4Editor-Core.dll {0x00007ffccbec9dd8} + 0 bytes

 UE4Editor-Core.dll {0x00007ffccbeaa7a2} + 0 bytes

 UE4Editor-D3D11RHI.dll {0x00007ffcc26f4fd4} + 0 bytes

 UE4Editor-D3D11RHI.dll {0x00007ffcc26efe51} + 0 bytes

 UE4Editor-D3D11RHI.dll {0x00007ffcc269300f} + 0 bytes

 UE4Editor-D3D11RHI.dll {0x00007ffcc26df7bc} + 0 bytes

 UE4Editor-D3D11RHI.dll {0x00007ffcc26fb586} + 0 bytes

 GFSDK_VXGI_x64.dll!VXGI::VoxelTexture::AllocateResources() {0x00007ffcc1f0bbe4} + 18 bytes [c:\p4\sw\devrel\libdev\gi\dev\bugfix_main\giworks\src\gi_voxe

 GFSDK_VXGI_x64.dll!VXGI::GlobalIllumination::AllocateResources() {0x00007ffcc1edc2da} + 8 bytes [c:\p4\sw\devrel\libdev\gi\dev\bugfix_main\giworks\src\gi_base

 GFSDK_VXGI_x64.dll!VXGI::GlobalIllumination::setVoxelizationParameters() {0x00007ffcc1ed92f1} + 11 bytes [c:\p4\sw\devrel\libdev\gi\dev\bugfix_main\giworks\src\gi_base

 UE4Editor-D3D11RHI.dll {0x00007ffcc26c5f19} + 0 bytes

 UE4Editor-D3D11RHI.dll {0x00007ffcc26d4260} + 0 bytes

 UE4Editor-RHI.dll {0x00007ffcddf3f819} + 0 bytes

 UE4Editor.exe {0x00007ff71a1dacee} + 0 bytes

 UE4Editor.exe {0x00007ff71a1d241b} + 0 bytes

 UE4Editor.exe {0x00007ff71a1d2a6a} + 0 bytes

 UE4Editor.exe {0x00007ff71a1e45e9} + 0 bytes

 UE4Editor.exe {0x00007ff71a1e55d9} + 0 bytes

 KERNEL32.DLL {0x00007ffce31913d2} + 0 bytes

 ntdll.dll {0x00007ffce4b35454} + 0 bytes

 ntdll.dll {0x00007ffce4b35454} + 0 bytes

I'd suggest just getting an official release off the official github page.

http://github.com/epicgames

You need to register your github account with them. You can follow the instructions here: https://github.com/EpicGames/Signup

when that is all done, you can get a official 4.8 release by downloading the zip at :

https://github.com/epicgames/unrealengine/tree/4.8

You can then follow the instructions to install a from-source version of UE4.

Otherwise, I'm pretty sure you can get 4.8 from the Epic Game Launcher that most devs are taught to start with.

Hopefully this helps :)