Lost network in Windows, possible reasons?

Question

Computer networks

There is no antivirus.
And does not even see the router. Any troubleshooters do not help. It does not respond to changes in firewall settings. Changing/changing network group settings doesn't help either. Removing and reconfiguring the connection on the drum. What else can be done?
This is not the first time this happens, "by itself" passes later, but I'm tired of puzzling over why this happens.

Answer 1

The physical connection must be intact: the light on the router must be on constantly.
If this is not the case, there are 3 reasons:
1. The network card in the PC has failed.
2. The cable from the PC to the router is damaged (or there are pickups).
3. The port in the router fails or (the router itself is completely).
If the physical There is a connection, but there is no traffic - the reasons are different:
1. Failure in the OS
2. The network card in the PC fails.
3. The port in the router fails or (the router itself is completely).
(check from top to bottom)

Answer 2

There is no antivirus.

- it ’s sad, you need to install something, at least
check the wheelbarrow for viruses from a bootable flash drive of the antivirus