How often does it happen? Take them to service center and have a test.

You said " I am unable to access via wireless or wired connection. "... You have no internet via wireless or wired connection but you can access its web interface at that time, right? Is it still...

Updated. Try the link again.

Did you try the instruction here? If it doesn't help, uninstall anti-virus software and disable firewall. Uninstall the driver and reinstall the driver. http://www.tp-link.com/en/faq-306.html

140827 is the latest version currently... On your main router, you didn't configure address reservation as well? That's weird... If it is convenient for you to assign static IP for all clients, you...

Wow, glad to see such a thread...Enjoy it...lol