Gigabyte Realtek Pcie Gbe Family Controller Driver

The problem is my Realtek PCIe GBE Family Controller isn't working all the time.
My system configuration - Windows 7 x64bit, Gigabyte motherboard, Intel cpu, 8 GB RAM, onboard gpu, onboard LAN.
After a clean windows installation and then everything running good for few days, suddenly the internet connection is lost and Realtek PCIe GBE Family Controller goes missing.
I go to the device manager and there I see 'Network Adapter' is entirely missing there. Then I check right side More Actions > View > Show Hidden Devices, and there I find the Network adapter but upon right clicking there is no options available. And if I expand it further there are all those WAN
miniports but no Realtek PCie GBE Family Controller.
Screenshot below-

No Realtek PCie GBE Family Controller there, a familiar nightmare for me nowadays.
What I've tried so far-
1. Trying to uninstall/install or disable/enable network adapter.
Wait! That's not possible because my entire Realtek PCIe GBI controller is missing and NIC has no right click options under device manager.
2. Tried updating new version of Realtek LAN driver.
That's too not possible because it can not even find the Realtek PCIe GBI controller. So there's an error message popping everytime I tried to do so.
3. Tried to change the Network adapter setting from Network And Sharing center. But there is no 'Local Area Connection' present as you can guess. It's completely a blank window folder. Troubleshoot says it can't detect Network Adapter.
4. Rebooted and reset the router.
Yes! Network Adapter menus, Realtek controller is back again, but not for long. Within few hours it's gone again and I'm back with no internet connection.
Bytheway, this trick worked only the first time, next time there's no charm left.
5. Remove the power lines from cabinet and router and connect those next day.
Ok, here's the fun part. Sometimes, remember not always, one or two times happened this, that I get back the Realtek PCIe GBI controller under device manager but then so after I switched on the router NIC is gone missing again! Not for a second the internet connection established there.
6. Format and re-install windows 7!
Did that (couple of time already), worked just for 1 or 2 days max, then again back to the same space. NIC missing, tray network monitor like icon is red crossed.
One thing, before my NIC would go missing again I removed the tick from 'Allow the computer to turn off this device to save power' option and saved. But that didn't save me!
7. Pull out the CMOS, RAM sticks, wait for few hours.
OK! NIC is back. Hoped that finally my problem is resolved.
Shoot me please - NIC is gone after a day.
Now you may think my wireless D-link router is faulty, but this entire time I can access my internet through my wireless router in my phone but not in my desktop which is connected to router via RJ45 cable.
Try another WAN port in router? Yes but result is same. No NIC appeared yet.
Maybe the RJ45 cable is faulty then!? Changed that too, but that didn't make NIC coming back from vacation.
If you're thinking some router configuration error then here is the settings from ipconfig-
Windows IP Configuration
Host Name . . . . . . . . . . . . : Home-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : FC-AA-12-15-63-47
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::15c:78d1:c9ed: de3e%11(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.0.2(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Thursday, March 23, 2018 7:42:44 AM
Lease Expires . . . . . . . . . . : Friday, March 24, 2018 7:42:44 AM
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DHCPv6 IAID . . . . . . . . . . . : 251236576
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-44-31-16-1C-FC-AA-16-17-75-37
DNS Servers . . . . . . . . . . . : 192.168.0.1
192.168.0.1
NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter isatap.{7898FB4B-D561-4881-A952-170254A2D03E}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Teredo Tunneling Pseudo-Interface:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
BIOS is up to date. Router is ok.
System is just 3 and half years old and router is 2 years old. System working fine except Network
adapter.
No VPN software or any other network related software installed. Antivirus Avast free. On installed softwares- just some basic pdf reader, media player, dvd writer etc.
Computer is used basically for studying and a little bit of gaming (everything on cryosleep now) and there is no additional GPU installed, only the onborad default one there.
Then why the hell my NIC is acting this weirdly lately??? For the last 3 years and so it's perfectly working fine as it should be and then suddenly this started to happen to my computer.
Do anyone here have any theory, explanation or SOLUTION on this weird NIC problem??
Urgent need ofHELP!! PLEASE!!!Anyone??