Yellow mark on wifi signal ?

If you're connect w/ good signal strength... check if the network now requires a password/network key. If that's not the case it's possibly offering local only because the router / modem are out of sync & need to be power cycled to resync / DHCP client to reconnect.

You first see the properties of wify connection icon and see that ip is showing or not . If not showing then click for repair the connection. Try again. If not succes, then call your administrator of ip provider follow his instruction.

There are many possiable error :

1.  Automatic IP Obtain Error 

2. Only LAN Connection working, No Internet Connection. 

3. Network Pass Key

4. Restart your Router and DHCP 

You need to add the user "LOCAL SERVICE" to the "Distributed COM Users".  You don't need the DNS fix nor the Admin group fix.

Instruction:

Computer/<left click>/Manage

Local Users and groups/Groups

<double click>Distributed COM Users

Add/local service

Check names, should capitalize

<Select OK>

By this sure it will resolve the issue permanantly.

Internet not coming or you not connected to internet

Windows is showing that you have WIFI simply because the connection from your wireless router to your computer is good. The yellow "!" can be an indication that your router is not communicating with the broadband modem or the broadband modem is not connecting to the internet. In many cases the router and modem are all in one and you can check these settings using the device interface. This is usally found by typing in the gateway address assigned through DHCP to each client on the LAN. The easiest way to start however, would be to power down the router/modem unplug it, and wait five minutes to plug back in and turn on. I would then power cycle my device to clear whatever cached information may exist on the network adaptor. Hopefully that will bring you back to the information super-highway. Good luck!

Restart the router and/or use ipconfig /release and ipconfig /renew command from command prompt. If you still have problem check the line with your service provider