Hello Indianacarnie & Brink-Shawn Sir,
I am very thankful to Sevenforums,MSchild,Indianacarnie & Brink-Shawn for your support. Shawn yours last advise worked!!! I got functional network icon after deleting all network adapters & drivers. Then on restarting laptop, Realtek PCIe FE Family controller driver got installed by default & got updated in Windows Update(on connecting to internet,pop up came for update). But cannot install Microsoft driver update for Broadcom 802.11n Network Adapter. I tried many time but it didn't installed got code error 80070103.
I did not Install official DELL drivers from DELL DRIVERS CD So "DO I HAVE INSTALL ORIGINAL DRIVERS FROM DELL?"
As Indianacarnie said running the sfc/scannow file checker three times in a row, rebooting between each run did not resolved the error, instead sfc/scannow said detected corrupt files but unable to fix it. Now WHAT to do sir?
CBS generated 9.86mb file, but I copied whole date & created ms word file of 1.17mb. I request Indianacarnie & Brink-Shawn Sir to open my ms word file,check last part of file where problem must have mention and decode technical data in layman way. Please point the files to me so that I can replace them after extracting setup cd by 7zip.
Also in my Spybot2-beta version tea timer function is absent. Something is better than nothing, So I kept spybot. Because Windows Defender cannot start & says
"The system cannot find the path specified (Code Error:0x80070003)
System restore point was over righted with new restore points as I installed software,windows updates & uninstalled software. So last point of problem free state was gone.
I encounter strange behavior of my network adapters, explained below in different scenario, explained with attached labeled images:-
#Connecting Internet via LAN cable-(BEFORE DELETING network connection)CASE-1
In network & sharing center>change adapter settings>
I found
Local Area Connection-Realtek PCIe FE Family controller,
Wireless Network Connection-DW1501 Wireless-N WLAN Half miniport adapter &
Wireless Network Connection 2-Microsoft VirtualWiFi miniport adapter.
When I connected internet via lan all adapter were shown & named, but red cross persisted.
#Connecting Internet via Wifi-(BEFORE DELETING network connection)CASE-2
I found only
Wireless Network Connection-DW1501 Wireless-N WLAN Half miniport adapter &
Wireless Network Connection 2-Microsoft VirtualWiFi miniport adapter.
NO
Local Area Connection-Realtek PCIe FE Family controller. LAN port/adapter was absent in the list. I was confuse on its absence & red cross persisted.
#Connecting Internet via LAN cable-(AFTER DELETING network connection)CASE-3
After deleting all network adapters with removing it drivers, I restarted laptop.Then LAN driver got automatic install from Windows update and got update from internet as I connected LAN cable. Then network icon worked perfectly fine.

Problem solved. But name of adapters were absent.

Wifi driver were got installed via internet when I clicked Check for updates in Windows Update via lan cable
#Connecting Internet via Wifi-(AFTER DELETING network connection)CASE-4
To check my wifi adapter I disconnected LAN cable, the moment I removed LAN cable my LAN adapted was missing In Network Connections.

What is this problem now ?
Why so, before deleting network connection, internet connection via wifi showed lan adapter in Network Connections, but after deleting network connection, internet connection via wifi DID NOT showed lan adapter in Network Connections
Why this happens?What should I do to maintain LAN adapter even after dis-connecting LAN cable?
Please help, my patial problem is solved, only sfc/scannow result interpretation & this missing LAN adapter is bugging me. Please help me Sir.
Thank you lot for getting me working icon...