Wireless Issues - Network Shares

Hey guys, I have just switched internet providers and they gave me a modem/router and now my wireless network shares are all screwed up.  I can go into network shares and find my router and connect to it.  I can actually go on youtube as well but when I try going into network shares, I get nothing.  I had this working with my previous internet provider where I had a router hooked up to the cable modem.  Anyone have any ideas?  Thanks