My built in network adapter is gone (deep sleep)

The issue is my internet connection is gone. I've checked and my Realtek network adapter built into motherboard is gone from devices manager. I've tried installing different version of the driver but it doesn't let me do that. All I get is an error message: "The Realtek Network Controller was not found. If Deep Sleep Mode is enabled Please Plug the Cable." First of all the cable is plugged in. Everything is as it's supposed to be and has been before. I've also tried removing RAM sticks and battery to reset CMOS. I have also reset the CMOS from BIOS. I've checked BIOS for anything such as green power modes etc. Nothing like that is enabled. LAN H/W option is enabled and the other one BOOT LAN or something like that, should be disabled and is disabled. No more ideas what I should do next. Even tried reinstalling the system, without any progress. I can't see my Realtek in devices manager, internet connections, nowhere. My motherboard is Z68X-UD3P-B3. No driver allows me to go through the installation process because of the deep sleep error. I cannot turn that off in any way because I have no options to do that. My adapter is unrecognizable. I don't want to buy a PCI network card as this has been working yesterday.