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NET SendPacket ERROR WSAEINTR (Winsock error)

I get this error: "NET_SendPacket ERROR: WSAEINTR (winsock error) A blocking operation was interrupted by a call to WSACancelBlockingCall." when I try to run Steam or connect to a server - what should I do?

Common Causes


  • Network card drivers need to be updated
  • Default client port (port 27005) is already in use
  • Bad Winsock DLL
  • Bad TCP/IP stack
  • Firewall
  • Internet Connection Sharing (ICS)
  • VIA KT133A motherboard chipset w/o proper 4-in-1 patch

The recommendations provided here may also help in addressing other WINSOCK errors:



Remove all references to Steam.exe and HL.exe and let them be re-learned. Be sure to give permission for all TCP and UDP ports.


Update Network Card Drivers
  1. Exit Steam
  2. Right-click on the My Computer icon and go to Properties
  3. Select the Hardware tab and click the Device Manager button
  4. Locate the name of your network interface card under the Network Adapters node
  5. Search for the card manufacturer's website to locate and install any necessary driver updates


Bad Winsock DLL

Please see the help topic which addresses repairing common Winsock errors.


Bad TCP/IP Stack
  1. Exit Steam
  2. Go to the Start button and select the Control Panel
  3. Open Add / Remove Programs
  4. Select Windows Setup on the left side of the window
  5. Remove any Communications components
  6. Reboot your machine
  7. Repeat the procedure while selecting the Reinstall option for the Communications components which were previously installed
  8. Re-add TCP/IP in the Network Properties for your network interface card


Conflicting Ports

Add +clientport 27025 to the Launch Properties for Steam.


Internet Connection Sharing (ICS)

ICS is not compatible with Steam. You will need to disable ICS to use Steam.


VIA KT133A Motherboard Chipset

Check your motherboard drivers and, if you are using a VIA KT133A motherboard chipset, please visit to get the 4-in-1 patch.


Problem with Steam?

Contact Steam Support
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