Turn off the computer, then turn off the router, then turn off the modem (if it's a separate modem). Wait for 10 minutes, then reverse the process.. Turn on the modem, wait two minutes for it to reinitialize, then turn on the router, wait two minutes, then turn on the computer.
In addition, many will have problems when they disable the SSID broadcast in the router settings.. Make sure the SSID is not disabled.
Tried changing channels on the router? Some channels may experience interference where others will work fine.
If that still doesn't fix the problem, then try using a second laptop to confirm the problem is with the router and not with the laptop.. If the problem still occurs with a second laptop, think about replacing the router.
Hope this helps.
My laptop say "Windows Cannot Connect To Netgear", which is my router. It's 15 feet away and I can connect to it fine usually. Sometimes I'll be doing something and my laptop cannot connect to my router, it will say "Windows Cannot Connect To Netgear" even though it appears in the network list and I can connect to other routers just fine. My router uses WPA-Personal/AES. What can I do to correct this problem.