A socket error, such as socket error 10051, occurs whenever one computer attempts to connect to another network or server. Error 10051 happens because the other network is unreachable, usually because there is a problem with the router or modem on the computer attempting the connection. This can be as harmless as the router being shut off or a firewall getting in the way. At the serious end of the spectrum, the router may be misconfigured or may have been destroyed and is nonfunctioning.
Whenever a connection cannot be made, such as in the case of socket error 10051, one of the most common culprits is a firewall program. Though made to keep the computer safe, a firewall may restrict friendly connections. One should disable the firewall and see if the connection can go through. If the socket error still appears, then the firewall is not at fault.
If the router or modem is down, then there is no way for the computer to connect to another server. Someone may have bumped into the router or meant to reset the router and never turned it back on. Turning the router back on should restore the Internet server and allow the computer to connect to a server. If the router has been damaged, by being hit or having liquid spilled on it, for example, the router may need to be completely replaced.
A misconfigured router can cause socket error 10051. The misconfiguration means the router believes it cannot communicate with the server, so it doesn’t attempt the connection. Some advanced users may be able to find the problem, but it is best to call the Internet provider and get someone there to check out the router configuration. The provider will be able to find the problem and will tell the user how to fix it.
Some users have more than one router active at the same time. If there is more than one, one portion of the computer may believe it has to talk with one router, while another section believes another router has to be used. In this instance, neither router is designated as the primary router so neither will work. Configuring the computer to speak with only one router will alleviate this problem.
A similar problem that some users believe can cause socket error 10051 is when the computer is told not to use any router. This would cause the network to be unreachable, but it yields a different socket error. When the computer doesn’t have any router configured, this returns a socket error 10065.