Did you contact your ISP? As I checked the emulator, it says "You may configure this function under your ISP's instructions.".

You can restore the settings using the backup file because it doesn't say that the configure file of old firmware cannot be used in this firmware in notes like some other models.

When the PC shows No Internet Access, can you login http://192.168.0.1? If you can, check if there is WAN IP address on Status page. On System Tools---Diagnostic page, ping www.google.com and ping...

I called the store, they said that this router can accomodate even up to 250 users. It is not right. It only allows maximum 10-15 clients to connect at the same time. The router is not as powerful as...

Did you check if the adapter still shown up in network adapters or other device(computer management---device manager)? I don't think it is an adapter issue since it is working on another computer....

What's the firmware version of your WA830RE? Is it the latest version? How about status of RE light when connection drops? Without the extender, how many bars of signal strength receiving from the...