So I here is the initialization of a game:

//initialize Direct3D
		this->p_d3d = Direct3DCreate9(D3D_SDK_VERSION);
		if (this->p_d3d == NULL) {
			return 0;
		}
	
		//get system desktop color depth
		D3DDISPLAYMODE dm;
		this->p_d3d->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &dm);
	
		//set configuration options for Direct3D
		D3DPRESENT_PARAMETERS d3dpp;
		ZeroMemory(&d3dpp, sizeof(d3dpp));
		d3dpp.Windowed = (!fullscreen);
		d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
		d3dpp.EnableAutoDepthStencil = TRUE;
		d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
		d3dpp.PresentationInterval   = D3DPRESENT_INTERVAL_IMMEDIATE;
		d3dpp.BackBufferFormat = dm.Format;
		d3dpp.BackBufferCount = 1;
		d3dpp.BackBufferWidth = width;
		d3dpp.BackBufferHeight = height;
		d3dpp.hDeviceWindow = p_windowHandle;
	
		//create Direct3D device
		this->p_d3d->CreateDevice(
			D3DADAPTER_DEFAULT,
			D3DDEVTYPE_HAL,
			this->p_windowHandle,
			D3DCREATE_HARDWARE_VERTEXPROCESSING,
			&d3dpp,
			&this->p_device);
	
		if (this->p_device == NULL) return 0;
	
		//clear the backbuffer to black
		this->ClearScene(D3DCOLOR_XRGB(0,0,0));
	
		//create pointer to the back buffer
		this->p_device->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &this->p_backbuffer);
	
	    //use ambient lighting and z-buffering
		this->p_device->SetRenderState(D3DRS_ZENABLE, TRUE);
		this->p_device->SetRenderState(D3DRS_FILLMODE, D3DFILL_SOLID);
        this->p_device->SetRenderState(D3DRS_LIGHTING, true);
		this->SetAmbient(this->p_ambientColor);
	
		//initialize 2D renderer
		HRESULT result = D3DXCreateSprite(this->p_device, &this->p_sprite_handler);

I put the code here just to show that there is no viewport creation,just in case.

My problem is,that when I resize the window,the images get distorted.I tried to think about a solution but I can't find one.

Can someone make a suggestion?

that's not the problem...i know from the past that the images will still be stretched...