Reconfiguring wireless network

Temporarily, move the AirPort Express close to the TC and connect a spare Ethernet cable.....any length will do....from one of the three LAN <--> ports on the TC to the WAN "O" port on the AirPort Express

Power up the Express for a minute or two

Hold in the reset button on the Express for 7-8 seconds and then release. Allow a full minute for the AirPort Express to restart

Click the WiFi menu at the top fo the Mac's screen and look for a listing of New AirPort Base Station. Just under that listing, click directly on AirPort Express

The setup "wizard" will open up and take a few seconds to analyze the network. Then, a screen similar to the example below will be display, except that you will see your devices pictured, and the name of your wireless network.

Type in a short name that you want to call the AirPort Express

Click Next

Watch the next screen carefully to verify that the Express is being set up to extend using Ethernet. This will confirm that the setup wizard has picked up the Ethernet connection between the TC so the correct settings will automatically be applied to the Express to extend the network

When you see the message of Setup Complete, click Done and you are done.

Now move the Express to the location where it will be needed and establish the long Ethernet cable connection from the TC to the Express. If the long Ethernet cable is working correctly, so too will the AirPort Express be working correctly.

OK, here is what I would suggest:

Temporarily, power off the TC and move the TC close to the Asus router

Use a spare Ethernet cable.....any length will do.....and connect it from one off the LAN <--> ports on the back of the Asus router (there are usually 4 Ethernet ports, use any one that you want) to the WAN "O" port on the TC

Power up the TC and let it run for a minute or two

Using a pen or something similar, hold in the small reset button on the back of the TC for 7-8 seconds, then release

Allow a full minute for the TC to restart

Click the WiFi menu at the top of the Mac's screen

Click directly on Time Capsule just below the listing of New AirPort Base Station

When you click on Time Capsule, that will start up the AirPort Utility setup "wizard". It will take a few seconds to display a screen that looks like the example below, except that you will see your Time Capsule pictured.....not an AirPort Express as you see below.

Network Name......Type in the exact same wireless network name that the Asus is using

Base Station Name.....Type in a short simple name that you want to call the Time Capsule

Password......Type in the same password that the Asus wireless is using

Verify......Type in the same password again to confirm

Click Next

The "wizard" will set up everything for you correctly and automatically. When you see the message of Setup Complete, click Done.

Now the TC has been set up correctly. When you have the long Ethernet cable installed, move the TC where it will be needed and make the connections, power up the TC, and you are all set.

Post back when you have completed the setup and installation of the TC and we'll set up the AirPort Express.

Will the AirPort Express use the same wireless network name as the Asus as well, or do you want to set up a different network where the Express will be located?

I tried to connect the tc to the WiFi but it was not found

You can do this, but it will take an older 5.x version of AirPort Utility to do it. If you have an older Mac running Leopard (10.5.x) or Snow Leopard (10.6.x) or a version of Lion up to 10.7.2, you can set up the TC the way that you want....to connect using only wireless. A PC with AirPort Utility for Windows installed should work as well.

Note.....I'm not recommending that you do this, since you will have what is known as a "double hop" wireless setup.....I'm simply saying that it can be done.

I have had to put an airport express in the loft and connect it to the tc by Ethernet

That is unfortunately really going to limit performance, since there is always going to be a significant loss of speed when the Express connects using wireless....plus, the Ethernet port on the Express is limited to only 100 Mbps, while the TC will support up to 1,000 Mbps.

If you could connect the TC back to the main router using a wired Ethernet cable connection, that would be a much better setup, and the TC could be additionally be configured to "extend" the network that the Asus wireless router is currently providing.

If you cannot run the Ethernet cable......highly recommended.....you might be able to use a pair of Ethernet over powerline adapters to send the signal from your Asus router to the TC over the existing AC wiring in your home. The theory with the adapters is that you already have the wiring in place, you just need the adapters. In practice, things don't always work as well as the theory suggests though.

Once that is set up, you could have an AirPort Express, or better yet, an AirPort Extreme wirelessly extend the signal from the TC to provide additional wireless coverage. Again, better to connect using Ethernet, but that might not be possible.

As you have guessed, a simple network setup is always going to work better and more reliably than a more complex network.....and....a network using an Ethernet "backbone" will always provide better performance than a network that uses wireless to connect back to the main router.

Let's take one thing at a time to avoid confusion.

If you can run an Ethernet cable from the Asus to the TC location, that would be by far the best way to connect the TC......and.....the TC can also be configured to extend the wireless network signal that the Asus is providing.

Is that what you want to do, or do you plan to keep the WiFi turned off on the TC because you don't need additional wireless coverage in the area where the TC is located?

Either way, the TC will need to be reset back to its default settings and then set up again to connect using Ethernet. Then, establish an Ethernet connection from one of the LAN <--> Ethernet ports on the Asus router (there are probably four of them) to the WAN "O" port on the TC.

When the TC is set up and working, then you can work on the AirPort Express. Start by resetting the Express back to its default settings first.

Then, establish an Ethernet connection from one of the three LAN <--> Ethernet ports on the TC to the WAN "O" port on the AirPort Express.

If you need more tips on the setup, we need to know whether you will be using a Mac, a PC, or an iPhone/iPad to set things up. If you have a Mac, we assume that it is running a current or recent operating system, correct?

We can provide the step by step instructions that you need, but in order to do that, we need to know whether you will be using a Mac, a PC, or an iPhone/iPad to set things up. If it is a Mac, we assume that the Mac is running a current or recent version of the Mac operating system, correct?

Nice work!