D-Link DIR-655 :: Will Not Connect To Other PCs

 I had a dual channel netgear n600 set-up at 2.4 GHz working with three machines. I replaced it with the DIR-655 using my laptop to get better signal levels on one distant PCs . I setup the router from the laptop (win7)  with the DIR-655 connected to the Cable modem output and did the set-up. Used the wizzard and the laptop is now  working fine on the wireless network .  Then  went to other machines and the wireless signal as indicated by the laptop was fine. I reset the networking details on these PCs (Win 7 and win XP) and used the assigned network name, dlink, the security / pass key and same WPA security as prescribed on the DIR-655 router - to set up the network connection on these machines. The network adapters are fine on these machine but they will not connect to the dlink router. The win XP PC sees the network but the Win7 machine will not even see the network.   Have doubled checked all the settings and I cannot see that anything is wrong with the settings ?? Note I do have an apple iphone that seems to be picking up the signal fine. Have  turned off the  modem and router numerous time but still have same problem.

At one point I had to return to the preset DIR-655 settings since the ID and pass word I had set would not longer allow me to access the router ?? I also notice that one D-Link panel says the UID is Admin whereas it was originally shown to be admin but could not be changed