The internet is always falling off the line what's going on

If the external network is easy to disconnect, and the intranet is normal, then first check whether the use of third-party firewalls caused by:

Problem is still in, log in to the router background to see if the connection to the extranet is normal:

If you are using Dial-up networking, you can first log in to the router background to see if the WAN port connection status is normal:

Of course, if the wireless connection, then switch to wired;

Conversely, if the cable is connected, then use the wireless connection to see whether it is normal, because the cable connection may have the phenomenon of loose interface;

If you have determined that the extranet is normal, and often the native connection is disconnected, but Ko, then check the problem on this machine.

Right-click the Network connection icon and select Status:

In the pop-up dialog box, click Properties:

Then click the Configure button directly in the pop-up dialog box:

Then switch to advanced, select Connect speed and Duplex mode, try to change the value, click OK to save the settings until normal: