I have the other day installed cable internet, which came with it's own modem and router, where I previously had 3G.

My 3G router had the IP address 192.168.2.1, and in the IPv4 settings of the Local area Connection this IP address was set as default gateway.

The new router I gave IP address 192.168.2.2 and the PC detects this as Network 2, works fine after all, but in the IPv4 settings of the LAC is still *.*.*.1 as default gateway however that router currently isn't even attached to the system anymore.

In my router's routing table it shows gateway as 192.168.2.0, so that is what I just now entered as default gateway in my IPv4 settings, and it doesn't make any difference.

Next when I click on details in my LAC it shows 192.168.2.100 as IPv4 default gateway, but in properties it shows 192.168.2.0.

So what should be my correct set up?

I'm a bit confused as to what you're doing here (with what equipment).

If you are pulling the old router (192.168.2.1) out of the equation, then the new router should take its place as 192.168.2.1.

Deeper Explanation:

If you have TWO or more active router/gateways active on the same system, and they both are providing DHCP service to connected Ethernet devices for automatic/Dynamic IP, DNS and Gateway acquisition when they connect to the network -- then having the TWO DHCP services active will conflict.

Also, if you have manually set STATIC IP, DNS and Gateway on any connected device, they will ALWAYS use the Gateway set in that setup.

Easiest thing to do is to make the new modem/router take the exact place and settings of the previous setup.

Give us a make and model of the router, and if possible a screenshot of your set up screen (blanking out your passwords etc) and someone will be able to help you out.

I'm a bit confused as to what you're doing here (with what equipment).

If you are pulling the old router (192.168.2.1) out of the equation, then the new router should take its place as 192.168.2.1.

Deeper Explanation:

If you have TWO or more active router/gateways active on the same system, and they both are providing DHCP service to connected Ethernet devices for automatic/Dynamic IP, DNS and Gateway acquisition when they connect to the network -- then having the TWO DHCP services active will conflict.

Also, if you have manually set STATIC IP, DNS and Gateway on any connected device, they will ALWAYS use the Gateway set in that setup.

Easiest thing to do is to make the new modem/router take the exact place and settings of the previous setup.

I always give all devices connected to my network a static IP, so I gave the new router that IP address manually.

I have 3 routers include the one that came with the cable internet, which is a Tenda 300M.

The other 2 routers are set as access point, but I just notice that the router to which previously my 3G aircard was connected has DHCP server enabled.

So I assume that I should disable the DHCP server on the previous router, correct?

In the Tenda router internet connection is set to PPPoE and DHCP server is enabled.

The 3rd router has DHCP dissabled.

In the router DHCP server I can set the client start IP and end IP. What IP addresses should I set there?

My routers are 1 - 2 and 3, but my cameras, PC, server and other devices connected to the network all have a static IP address above 150.