@hirenpar 

Hi, may I know if you still have both two issues after reinstalling the latest driver?

You can't find the 5GHz network of the adapter and the 2.4GHz network drops internet every 20-30 minutes, right? May I know how the 2.4GHz network recovered the internet?

Only the 5GHz network of the adapter can't be found on your PC, right?

If so, please change a different network name for 5GHz network of the adapter and change the router's 5GHz Wi-Fi channel to be 36/40/44 to check if you can see the 5GHz network of the adapter again.

For the 2.4GHz network drops internet issue, please also change the router's 2.4GHz Wi-Fi channel to be 1/6/11 to check if the issue happens again.

BTW, may I know when and where you bought the product? When the issue begins to happen?

Look forward to your reply.

@Kathy_Z 

I am using Belkin N600 DB Wireless Dual-Band N+ Router.

i tired band suggested by you for 2.5GHz and I see when I use channel 1 it shows improvement but will have to chk more 2-3 days.

i tired all bands given by you for 5GHz but none worked. still it doesn't show any 5GHz networks on my machine.

i was not able to get 5GHHz from last 5-6 months and this disconnection from 2.5GHz started after latest 2004 windows update.

thanks

@hirenpar 

Hi, may I know when and where you bought the product?

Have you saved the purchase proof?

May I know your region please?

Look forward to your reply.

@Kathy_Z 

i bought this in India via amazon.in on Ordered on 19 September 2016 

@hirenpar 

Hello,

You may need to contact the local tech support to check the warranty cause the device seems faulty.
https://www.tp-link.com/en/support/contact-technical-support/#Hotline-Support 
Good day.