Error

Network error 10091: "Network subsystem is unusable"

 

Error description

The error usually occurs on a very poor connection, for example, a laptop's Wi-Fi connection via a 3G hotspot and a loaded mobile network. In this case, there is a connection, but the delays are too long, tens of seconds.

 

Problem solution

1. Network drivers are missing or corrupted:

  • TCP/IP protocol is deleted or not installed;
  • network card driver is corrupted;
  • antivirus or firewall is deleted or disabled; the system starts displaying 10091 network error.


Run the command netsh winsock reset in the console to reset Winsock settings. 

Launch ncpa.cpl — is at least one network adapter is on?


Network adapters


Check in devmgmt.msc for any errors in network drivers


2. Virtual machine issue:

Virtual machines (Hyper-V, VMware) often are not assigned with adapter. No connected network and Winsock detects the subsystem as "unusable".


Assign network adapter.


3. Necessary network Windows Services are not launched:

  • For example: "DHCP client", "TCP/IP Support", "Network Connections", "Winsock Helper".


Open services.msc, and find:


DHCP Client

Network Connections

TCP/IP NetBIOS Helper

Winsock Helper Service (if any)


All these services must be enabled and work.