WiFi not connecting..not much info..any help appriciated!!!

[potere scuro]

I am at work right now but my buddies desktop XP is not picking up the WiFi. I am a little new with wireless connections but when i was looking at it his subnet mask was set to 255.255.0.0 the one he has up stairs is connected to a router and it is working with 255.255.255.0  school taught me that it is supposed to be like this but i don't know much about this WiFi. the wifi also has no DNS number. i know how to change the subnet but don't know what to do for the DNS. Any suggestions about this or what else i need to give y'all to be able to help me. Any replies would be much appreciated.
  thanks, C

[DaveLembke]

If his network wirelessnetwork is setup with DHCP enabled to spit out IP leases, it should issue an IP and as long as network properties are set to obtain IP and DNS you should connect. If security has been enabled you will need proper credentials to connect such as WEP or WPA Key or Passphrase etc.