Suddenly a few days ago, without changing any settings or anything, my LAN stopped working. I checked the LAN cable by plugging it into a laptop, it worked fine. Plugged it back into the PC, same issue persisted. So, since the LAN cable and router were OK, and the LAN port was also lighting up, I thought it must be a driver issue. I went to device manager and checked under every category, I couldnt find my LAN driver(Realtek driver) anywhere.So,I downloaded the driver from my motherboard manufacturer(Gigabyte H61M-S1) and tried to install it but at the end, an error pops up saying "Realtek Ethernet Controller was not found.If Deep Sleep mode is enabled, please disable it and plug in the cable". Did some research, turned the BIOS upside down to find something related to LAN or Networking or Network controllers which was disabled(didn't find any, everything was enabled, including Onboard LAN Controller), Reset the BIOS to default, reinstalling Windows, even took out the RAM sticks and CMOS battery, kept them out for a night, put them back in but to no avail. I have a CS tournament coming up in a few days and would really appreciate someone helping me to fix this. Thanks in Advance