Suggestion for LAN IP address

I have ADSL with WiFi. This uses 192.168.x.x.
I want to connect my home theater to my PC via LAN. If I plug an Ethernet router in, it uses IP 169.254.x.x
So of course Firefox and Thunderbird try to use this for Internet access.
So I need to change the LAN router to a higher IP metric. Any suggestions, or does it not really matter?
Currently I am not sharing my media files via the Internet.

EDIT: I think this info is more correct:
ADSL modem:
Gateway 192.168.1.1
Subnet 255.255.255.0
Wireless Network Connection
Internet

LAN modem:
Gateway 192.168.2.1
Subnet 255.255.0.0
Local area connection
No Internet

If I plug the LAN modem in Windows uses it for Internet, even though it has a higher metric than the ADSL modem. So no Internet.

Isn't this the opposite of what is supposed to happen? How can I fix it?

If you are getting 169.254.x.x with your router I believe its DHCP server was stopped. Go into its management interface and enable it.

Also plug the Ethernet cable to one of your ADSL modem/router's normal ports (if there are 4), then plug the other end to LAN router's WAN port (usually different color).

Then plug your PCs to the LAN router's normal ports.

@GokAy The problem with this solution is that there is a passage between my PC and the ADSL cable point. That is why the PC is connected to the ADSL modem via WiFi.
I used to be able to do this when I had a wireless Internet connection (iBurst.) Different IP range, of course.

What I said doesn't interfere with any WiFi.

Perhaps a bit more info is needed. Anyway, is the following true?

Your PC is connected to ADSL modem/router with Wireless.
Your Home Theater is connected to LAN router with a cable.
And they don't see each other?

Do you need a second router in the LAN? What happens when you disable DHCP on LAN router (I guess this is the case now) and connect the ADSL cable to a normal port on the LAN router, and other PCs connected should get an IP from the ADSL that way (using the router only as a switch)

I hope I was clear. If not, please describe each port of your ADSL and LAN modem/routers, where they are connected to and what IP they get.

@AddRAM I think that is Local Area Connection 2, which is the iBurst adapter. No longer used. Now unplugged. And that IP no longer comes up.

@GokAy

ADSL modem plugged into telephone socket. No LAN ports used at all. Gateway is 192.168.1.1. PC IP is 192.168.1.2.

The router that I last used about a year ago is a 3G USB wireless modem with 4 LAN sockets and a WAN socket. The 3G USB port has never been used. The wireless part is no longer used. Gateway is 192.168.2.1. DHCP for LAN enabled, range 192.168.2.100 to 192.168.2.255. The home theater is connected to a LAN port on this modem. If I check network status on the home theater I see that the router assigned 192.168.2.101 as the home theater IP.

If I plug a cable from the PC Ethernet port to the router, the router assigns 192.168.2.100 to it. Internet connection lost. If I map the networks, the Wireless Network Connection shows Internet access (although I do not have access.) The LOcal Area Connection mapping fails: "Responses from other devices on the network are delayed, or there is an incompatible router on the network."

I can ping the home theater. I can ping the LAN router gateway. I can ping the ADSL router. The home theater says the LAN is working. It does not offer the network as a source.

Ok, makes more sense now. Even though I would try other setups.

As I understand, your Home Theater doesn't access the Internet.

If you are only connecting PC and Home Theater and these are 1000Mbps Ethernet ports, you can just use one cable between them, no need for a router.

Or manually assign the LAN TCP/IPv4 properties on both computers, 192.168.2.0 network, 255.255.255.0 subnet but no gateway, gateway is only needed to reach foreign subnets.

If you configure the metric, smaller should be preferred (as far as I remember). It is possible cable has a higher metric than wireless.

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Everything's is possible if you configure them right :P

I used to have my laptop connected via cable to the 2nd port on my desktop. Gave them a second subnet manually and all was good.

It is the same as what OP is doing but without a DHCP assigning a second gateway.

macnab said:

~~~
If I plug the LAN modem in Windows uses it for Internet, even though it has a higher metric than the ADSL modem.
~~~

The metric won't matter if the Wireless network adapter disables itself when a wired connection is detected. The driver for your Wireless network adapter might not have this feature, but you might want to check:

OP mentioned he could ping ADSL router (wireless connection) so most likely they work together (post #6 last paragraph). However, hmm, maybe an incorrect DNS entry coming from the DHCP of wired connection.

Can you "ping 8.8.8.8" for example?