Wireless problem

My old computer is using wireless network hardware, however, I have installed the driver for wireless and restarted my computer. Once it
Gets to desktop and click refresh network list, how come the wireless network doesn’t detect my wireless router. It works on my pc whilst old pc doesn’t, so what’s the problem with it? Anyone know?
Answer #1
A number of things can cause this, are you sure your computer is detecting the wireless card? Are the correct drivers installed? Is the hardware enabled?
Answer #2
I said I install the driver, everything in device manager says all working and enable. It just won’t find my wireless router for some reason. Both supports 802.11g but still it just won’t, any other idea?
Answer #3
Come on guys, I really need help with this.