Static Routes on Windows - Computer with two NICs connected to two routed networks

Solution 1:

A quick stab with the following assumptions:

Router A has IP address: 192.168.4.1, and has correct routes/or its default pointing to 192.168.4.10
Router B has IP address: 172.168.4.1, and has correct routes/or its default pointing to 172.168.4.10    

You need to route 192.168.1.0/24 and 192.168.2.0/23 to 192.168.4.1 You need to route 172.168.1.0/24 and 172.168.2.0/23 to 172.168.4.1

so

  route -p add 192.168.1.0 MASK 255.255.255.0  192.168.4.1
  route -p add 192.168.2.0 MASK 255.255.254.0  192.168.4.1 
  route -p add 172.168.1.0 MASK 255.255.255.0  172.168.4.1 
  route -p add 172.168.2.0 MASK 255.255.254.0  172.168.4.1 

The -p will make them persistent across reboots.