Multi-homed server

I have a Windows 2003 server that I am trying to connect to both our internal network and our DMZ. I have the NIC1 (internal) set up as:
IP: 192.168.1.44
SM: 255.255.255.0
DG: 192.168.1.1

NIC2 (DMZ) connection is:
IP: 192.168.100.5
SM: 255.255.255.0
DG: (blank)

DNS registration is turned off on the DMZ connection and there is no entry on the DNS servers for this connection.

When connecting from the internal network, we are having speed issues, disconnects, etc. I’m not sure what the issue is.

Do I need to set up static routes on this machine? Why?