Why Asus Router Connects to One Laptop But Not Another?

Fix Asus Router not Connecting to Laptop:

First of all change the wireless channel.

If you don't know how to change then connect your Asus router via ethernet. Type Asus router's IP address i.e. 192.168.1.1 into the address bar of your browser.

Click on the Wireless tab. Beside "Wireless Channel," there is a drop-down menu.

Options are 1 (2.417 GHZ) through 11 (2.467 GHZ).

Select 1 and then Save Settings. Now get the ethernet cable out of the port and try connecting wirelessly.

If channel 1 doesn't work, then repeat above procedure until it works.

After reading your query it was clear that there is no problem with router and laptop 1 but your laptop 2 have some problem.

1. Just check that laptop 2 is not affected with virus or spyware infection, if it was severely affected then it can also be the cause of internet disconnection. You need to remove a virus or spyware from your laptop.
2. Another cause may be your antivirus program. Some antivirus program has built-in security that can cause internet disconnection. So for that check the configuration settings which are enabled.
3. You can also troubleshoot your wifi driver. You can uninstall your network driver and install it once again. And restart your computer. It should work.
4. Restart your router as well once. It can also help.

In the end, if everything OK then try to reinstall your driver and restart your Laptop.

First of all, connect to the router via ethernet and find your Asus router's IP address.

Type it into the address bar of your browser. Click the Wireless tab and beside "Wireless Channel," there is a drop-down menu. Options are 1 (2.417 GHZ) through 11 (2.467 GHZ). Select 1 and then Save Settings.

NOTE: Remember the channel it was already set to in case this is not a fix for you.

Now get the ethernet cable out of the port and try connecting wirelessly.