Unplug the router and modem's power cords from the power outlet for 15 seconds.
Plug the power cords back in.
Check that all cords and cables are secure at both ends.
Wait a few minutes, until the lights on the modem and router are working right.

Regards,
Peter

  @David-TP Even My wifi (tp link tl-wn881nd ) adapter is not connecting to wifi its US ver 

David-TP wrote

  @Shahzeb1 

Hi, would there be any error message when the adapter failed to connect to the wireless network?

It is also suggested to install the following driver manually:

https://static.tp-link.com/2019/201911/20191129/TL-WN781ND_V3.0 RTL driver 2023.56.0502.2017.zip

And since TL-WN781ND is quite an old version, if all the above suggestions did not work, it is suggested to return this one and get another model, like Archer T2U/T3U.

Thank you very much.

Best regards.

 

 

David-TP wrote

  @Shahzeb1 

Hi, would there be any error message when the adapter failed to connect to the wireless network?

It is also suggested to install the following driver manually:

https://static.tp-link.com/2019/201911/20191129/TL-WN781ND_V3.0 RTL driver 2023.56.0502.2017.zip

And since TL-WN781ND is quite an old version, if all the above suggestions did not work, it is suggested to return this one and get another model, like Archer T2U/T3U.

Thank you very much.

Best regards.