We afraid a little to remove routing from M$ cause we don't have spare domain controller and we don't know how to M$ behave after remove routing and second networkcard ..
In that case:
1.- Connect M$ 192.168.10.1 ethernet card to a Mikrotik ether port, say etherX
2.- Create a bridge, and add: etherX
and the mikrotik ether port being connected to Cisco SG500
3.- Assign 192.168.10.254/24 to that bridge
4.- Modify DHCP server as I specified on previous post regarding DHCP (setting 192.168.10.254 as default gateway).
Doing this all PCs will be able to reach all subnets,
as long as the proper gateway is set on them depending on subnet, e.g. if 192.168.20.1, 192.168.1.1 and 192.168.10.254 are assigned on Mikrotik router:
- All Devices (PCs or L3 switches) on 192.168.1.0/24 subnet should have 192.168.1.1 as default gateway
- All Devices (PCs or L3 switches) on 192.168.10.0/24 subnet should have 192.168.10.254 as default gateway
- All Devices (PCs or L3 switches) on 192.168.20.0/24 subnet should have 192.168.20.1 as default gateway