On some backburner machines you may get the following error:
ERR Error accepting connection: An operation was attempted on something that is not a socket. (0x2736).
This may be related to that machine being configured for IPv6, you can check if this the case if the IP addresses in the log file look like 1:2:3:4:5:6:7:8 iinstead of 126.96.36.199.
In most instances you won't need IPv6 and the simplest solution will be to disable IPv6, for details on how to do this please see Microsoft KB article kb/929852 (use option 5b).