Wireless Router Always Disconnecting

I do not temper with the routers and know nothing about them.

I have two routers (I think) one of them is called Linksys and the other is D-Link. Everytime I connect to the internet and use for awhile like 1-2hours, it will disconnect. And when it reconnects again, it disconnects pretty fast later on.

I’ve read an earlier post about the similar problem but I was stuck at some steps.

I right clicked Properties on Wireless Network Connection but there isn’t the Wireless Network Connection Tab. Mine just gave 3 tabs, General, Authentication, Advanced.