Please give full information for the question that you have asked to get a meaningful answer and please fill up your System Specs.
I presume you have asked about a Wi-Fi Network. Even if the all the detected Networks come up checked, how does that affect your connection to the Net?
Normally one has to choose from one of the available Networks and press the Connect Button. After that you may be asked to enter the Security Code to get connected.
My Computer
Computer Manufacturer/Model Number
Custom Built
OS
Windows 7 Pro with SP1 32bit
Motherboard
Intel D845GVS1 X86-based PC
Memory
2 gigs of RAM
Graphics Card(s)
Intel(R) 82845G/GL/GE/PE/GV Graphics Controller
Sound Card
Realtek AC'97 Audio
Monitor(s) Displays
Samsung SyncMaster 931BF Black 19" LCD Monitor
Screen Resolution
1280X960
Hard Drives
1. SAMSUNG SP0822N ATA Device ~ 80 GigaBytes
2. Seagate FreeAgent Go USB Device ~ 500 GigaBytes