Unreal engine install failed.the installation is corrupt

I am trying to install unreal engine 4.25.3.

I am getting installation failed message at verification process.

I tried allowing app through windows firewall.

also added all unreal and epic game domains in trusted sites.

now i dont have any clue.please help me.

I have check hard disk, memory everything is ok.

{
	"EndPointResults": [
		{
			"Type": "Endpoint",
			"Result": "Passed",
			"Code": "",
			"Desc": "Backend Connectivity Tests for https://account-public-service-prod03.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Failed",
			"Code": "TS-NC-0001",
			"Desc": "Backend Connectivity Tests for https://launcher-public-service-prod06.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Passed",
			"Code": "",
			"Desc": "Backend Connectivity Tests for https://catalog-public-service-prod06.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Passed",
			"Code": "",
			"Desc": "Backend Connectivity Tests for https://entitlement-public-service-prod08.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Passed",
			"Code": "",
			"Desc": "Backend Connectivity Tests for https://priceengine-public-service-ecomprod01.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Failed",
			"Code": "TS-NC-0001",
			"Desc": "Backend Connectivity Tests for https://lightswitch-public-service-prod06.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Failed",
			"Code": "TS-NC-0001",
			"Desc": "Backend Connectivity Tests for https://eulatracking-public-service-prod06.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Failed",
			"Code": "TS-NC-0001",
			"Desc": "Backend Connectivity Tests for https://friends-public-service-prod06.ol.epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Failed",
			"Code": "TS-NC-0001",
			"Desc": "Backend Connectivity Tests for https://epicgames.com"
		},
		{
			"Type": "Endpoint",
			"Result": "Passed",
			"Code": "",
			"Desc": "Backend Connectivity Tests for https://ue-launcher-website-prod.ol.epicgames.com/"
		}
	],
	"MinimumSpecResults": [
		{
			"Type": "Processor",
			"Result": "Passed",
			"Code": "",
			"Desc": "CPU: 2 Cores"
		},
		{
			"Type": "Memory",
			"Result": "Passed",
			"Code": "",
			"Desc": "RAM: 2GB"
		},
		{
			"Type": "Graphics Device",
			"Result": "Passed",
			"Code": "",
			"Desc": "GPU: GeForce 5, Radeon 9000, Intel HD Graphics"
		},
		{
			"Type": "Operating System",
			"Result": "Passed",
			"Code": "",
			"Desc": "OS: Windows 7 (or similar)"
		}
	],
	"RecommendedSpecResults": [
		{
			"Type": "Processor",
			"Result": "Passed",
			"Code": "",
			"Desc": "CPU: 4 Cores"
		},
		{
			"Type": "Memory",
			"Result": "Passed",
			"Code": "",
			"Desc": "RAM: 4GB"
		},
		{
			"Type": "Graphics Device",
			"Result": "Passed",
			"Code": "",
			"Desc": "GPU: GeForce 400, Radeon HD 5000, Intel HD Graphics 4000/2500"
		},
		{
			"Type": "Operating System",
			"Result": "Passed",
			"Code": "",
			"Desc": "OS: Windows 7 (or similar)"
		}