If you had an issue with yellow exclamation point showing over the network icon in Windows 7 (or Windows Vista) this may be caused by certain network related technologies which this operating system enables automatically. Sometimes, they can cause issues so you may need to disable them manually.
This problem may manifest after putting a lot of load under network (like for example – downloading or uploading a lot of files at the same time). Then you may experience network slowdowns or complete inaccessibility and a yellow exclamation point could appear over the network icon indicating a problem.
Although these tips may help, you should exercise them with caution and only apply them if you are sure what you are doing, because you will be modifying some low-level network settings. You should modify settings if you actually experience a problem with your network. If you want to return to original settings, this is possible too and it is described below.
Running an elevated command prompt
In order to execute these commands you need to open an elevated command prompt:
- Click on Windows orb (or press Windows key) to open Start menu
- Into the Search programs and files type cmd (or command prompt)
- Right mouse click command prompt icon and select Run as administrator – this will run command prompt in elevated mode
Viewing current network settings
In order to know the default values of the settings you are about to modify you need to view them. Type the following into command prompt and press Enter key to execute command:
netsh interface tcp show global
This will show you all the settings as they are currently configured so you may return them to original values if something doesn’t work properly. I suggest you remember or write these down.
TIP 1 – TCP Chimney Offload
TCP Chimney Offload option releases some of the workload from your CPU to the network card, whenever possible. If the network card supports this and it works correctly, then it should be enabled. But if it doesn’t work well, you may want to disable this by entering the following command:
netsh int tcp set global chimney=disabled
In case you encounter difficulties you can return this to default value which you can view using the netsh interface tcp show global command from before. So if it was set to automatic you may return it to original value by entering the following into the command prompt:
netsh int tcp set global chimney=automatic
The same goes for all of the following options.
TIP 2 – TCP Auto Tuning
Windows can automatically optimize your network for best performance, but sometimes they may also optimize it incorrectly, causing problems. Disabling this optimization may help – type into command prompt:
netsh int tcp set global autotuninglevel=disabled
As before you can return to default value by looking at it first using the command netsh interface tcp show global and typing the displayed value back into the above command.
TIP 3 – ECN Capability
ECN or Explicit Congestion Notification improves network optimization when a lot of data is being transferred back and forth. But it is not compatible with some routers so you may need to disable it. To do so type:
netsh interface tcp set global ecncapability=disabled
If you have a router that can support this, then you may also try to enable this option to see if there are some improvements.
TIP 4 – Receive Side Scaling
Receive Side Scaling or RSS speeds up things by utilizing your dual or quad core CPU cores. Once again, it may cause issues under certain occasions. To disable it type:
netsh int tcp set global rss=disabled
