OK -
to CF
Firstly, when you set up a wireless router, you normally need to start by plugging an Ethernet cable between the router and a PC to set it up. You mention an 'adaptor plugged into USB' - I assume this is a wireless adapter. Does your PC have an ethernet port on the back and is it close enough to the router to connect?
How are you able to post on here? By connectiing the PC direct to the cable modem, and if so have by ethernet or USB? Are you powercycling the modem between trying the router and direct connection?
Enough for now.