Most routers work in the private range of 192.168.2.x or 192.168.1.x - it sounds like you have changed your IP range.
Open up a CMD prompt and type IPCONFIG and hit enter - this will tell you what IP address your router has given you.
You then need to set your printer to be within the same IP subnet, so if your IP address is 192.168.1.1 then your printer needs to be something in the range of 192.168.1.(2 - 255).
Once you have done that you need to remove your existing printer from control panel and re-add it - specifying the IP address that you set the printer at.
Alternatively you could just plug your old router back in. If its a DSL router unless you are gaining extra bandwidth from going from DSL to DSL2/2+ you will gain little if anything from a new router other than the headaches your experiencing.