@Sud_1095 

Hi, for your issue, you have finished installing the adapter well but you can't get internet when you connected to the network of the adapter, right?

If so, please help confirm the below information first. 

1)  Connect other wireless devices to the router and make sure the internet is working with other devices.

2)  Check IP address, Default Gateway and DNS on PC when it connects wireless (Wi-Fi) network connection of the adapter.

You can follow the instruction to check. https://www.tp-link.com/support/faq/838/

If IP address is not obtained automatically, change it to Obtain IP Address Automatically.

If there is no IP address or invalid IP address 169.254.x.x:

Check the settings on router and make sure the network adapter is in the router’s white list. Normally a router would have mac filtering, access control or other kinds of firewall which can block devices. If he doesn’t know that, suggest him check it with router support, and he may choose to disable that function or add the adapter to the white list.

Please change router’s wireless channel to be 1/ 6/ 11 to check.

Uninstall the previous driver, try the latest one on our website or the one from chipset manufacturer to check if it works. https://www.tp-link.com/support/download/tl-wn821n/

If IP address is delivered by main router, please follow the instruction to try to ping the IP address of main router. https://www.tp-link.com/support/faq/425/

Look forward to your reply.