During installation, you installed the driver only, or you installed both driver and utility? In All Programs, can you find the utility and open it?

Check if the adapter has been identified or not. Right click on Computer and go to Manage. Go to Device Manager. Check Network Adapters or Other Devices. Try to unplug the adapter and plug it back to...

V9.2=V9.0 No worries. You can upgrade the latest firmware TL-WR841N_V9_150310 directly.

Sounds like faulty. If the firmware you downloaded is the right one and you upgraded the firmware by cable connection without power cut-off, you should be able to replace it under warranty. Contact...

Did you try the firmware Archer C7_V2_140318(Unifi & Maxis Fiber)? It is the latest firmware for Maxis users. http://www.tp-link.com.my/support/download/?model=Archer+C7&version=V2#tbl_j If this...

C7 should be able to WDS WDR4300. Follow the guide below to check your settings. http://www.tp-link.com/en/faq-440.html