1) Is your rtl8139 NIC really working?
Are you connecting your modem via USB or ethernet? If USB, have you tried it on ethernet?
2) With the DSL line disconnected and just the new router plugged into your PC via an RJ45 cable, can you browse to 192.168.0.1 and see the Netgear setup program?
3) If 2) is no. Does your other PC have an ethernet port as well as wireless? Can you connect to the router via its ethernet port?