How to connect another router to the modem and router pre-installed without changing any existing settings?

[TyKnee]

I have a modem and router installed in the office and I have run a 50m LAN cable from the modem to another router in the house to supply WiFi to the house as well. The existing modem and router were installed by the network providers so I can view the settings on my computer but I can't and don't really want to change their settings. The second router is a spare and I can make changes to the settings on there. It is currently setup as follows:
Modem - WAN - Router 1 (installed by the service provider)
I
WAN
I
Router 2 (done by me)

Currently each router is running its own network. The problem is Router 2 connects fine, but the connection slows down and drops consistently! Please could you help me fix this problem?
I can provide more information, like the IPs if needed? Thank you in advance

 

[g90814]

It sounds like you might have a bad cable between the 2 routers if you are having connection issues.

 

[Calculagator]

If it connects but then slows down and drops, you have a hardware problem. It could be the cable or it could be that your router is overheating and/or just doesn't have the power to deal with your network load.

 

[TyKnee]

It shouldn't be the cable because I did have it tested before I plugged it in. Here are some of the router settings which I can view on my computer:
Router 1: I can't change
DHCP - Yes
Ipv4 - 192.168.1.10
Default Gateway - 192.168.1.1

Router 2: I can change
DHCP - Yes
IPv4 - 192.168.2.8
Default Gateway - 192.168.2.1

 

[g90814]

Are you having connection issues on wired connections, wireless connections, or all?

 

[BadAsAl]

Why not setup router 2 as a wireless access point?
You connect router 2 to router 1, then setup router 2 as follows:
Turn off DHCP and firewall (router 1 acts as your firewall already)
Ipv4 - 192.168.1.9 (or make it 192.168.1.253, just need an IP that is not being used)
Subnet mask: 255.255.255.0
Default Gateway - 192.168.1.1

Configure the wireless on router 2 with the same SSID, encryption and password as router 1.
Your wireless network will be extended without losing any speed like a repeater would do.