What to do if network connections are lost?

Question

Computer networks

Good afternoon! I asked about the loss of internet. At that time, the system check with Dr.Web LiveDisk helped. And now, literally a month has passed, the problem is repeated on the same PCs (all updates are on 09/12/2017). But now the Dr.Web check showed nothing. After rebooting into safe mode, network connections disappeared. In the device manager, the adapter is displayed normally, I tried to reinstall the drivers. What kind of rubbish is this?
It costs Win7 Pro, accounting PCs with a bunch of bells and whistles (CryptoPRO, VLSI, ContinentAP) - demolishing the system is not an option.

Answer 1

1) after 3 days, put an ad on the wanted list, they will find your Internet.
If it does not help, then point 2:
2) contact a network specialist

Answer 2

Rolling back to a restore point didn't help?
Did uninstalling and installing drivers do anything?