How do routers go online frequently?

Failure Phenomenon:

A few days ago bought a tp-link router, referring to Tp-link's instructions to set up on the net. Thought this is all OK, did not think after a while off the line, the taskbar "network link" appears yellow exclamation point, prompted network access restrictions, and will automatically connect.

What's going on here? Is there a problem with the router and need to replace the router? In addition, my notebook is installed with the Windows 7 flagship system.

　　Failure resolution:

This is a "common problem" with Windows 7 systems that can be resolved by Group Policy settings.

1, first open the Group Policy window, in turn expand "Computer configuration → management template → system →internet Communication Management →internet communication settings";

2, and then in the right window, locate the "Turn off activity test for the Windows network connection status indicator," and then modify the property to "Enabled" after double-clicking.