Laptop won't find specific WiFi network

My sister's laptop (Dell E6400) won't find our home WiFi network. It finds the neighbor's networks just fine, as well as her school network at university, but not our home network. Already tried updating the WiFi drivers, but I think it's more of a problem with the router. Any ideas what to try next?

 

Does the network have a hidden SSID?
Some Wi-Fi cards have trouble seeing such networks even if you type in the SSID properly.

 

nope, the SSID is open/broadcasting. I've also tried resetting the router.

 

What is the router then? Is the firmware up to date?
Are some not typical signs in the SSID (like & % # etc)- there are some issues with those (I found that routers made in Germany or with German firmware tend to dislike <<@>> and <<">> signs for some reason)

What's the wireless channel on the router? Set if to a channel in the middle of a range like channel 6 for testing but nothing towards the end.

 

Are the router and card compatible types:wireless G or N etc?

 

Every wireless N device (be it a Wi-Fi card or a router) will automatically fall back to G when G device is present trying to connect. Even if the router was set to "n only" SSID should be visible.

The only possibility remaining is that the router is running @5GHz and the computer has a Wi-Fi card that's capable only of running @2.4GHz band.

 

Just to make sure set router to channel 1-11
Some wireless (most) can't see wireless over chancel 11 (but some can go up to channel 14 on g)

 

What router and adapter do you have? Also what wireless/security modes are you using?

Try running InSSIDer or other wifi analyzers

 

Router is a Motorola Netopia 3357, laptop is a Dell Latitude E6400 with an Intel 5100 card.

on a side note, the laptop used to find the network just fine in the past.

 

ran inSSIDer. It shows the neighboring networks normally, and our network very rarely - like it finds "wisps" of it from time to time (even though i was sitting right next to the router). I tried setting the router to variety of channels between 1 and 11, but nothing worked.

 

Do you have any other wireless devices to verify it's router's fault?
By the looks of it radio on the router may be failing.
If the router has any settings regarding transmit power turn it down if possible.

 

tried resetting the router. what's throwing me off is that my own laptops see the network just fine.

one thing i did notice is that the culprit laptop's WiFi driver is labeled "Intel 5100 Packetplaner-Miniport". Could this be the problem?

 

Probably is, update your drivers. Its using a windows given driver

 

i've tried that many, many times. also cleaned out the registry each time as well. but it seems like Windows is always beating me to it when it comes to re-installing. is there a foolproof way to reinstall a driver without Windows taking over and installing its one driver?

 

Install the complete Intel PROset tools and drivers, that should take over Windows Zero

 

So, quick update. Just installed Windows 7 Professional, 64bit. fresh install, new partition, the works. guess what? still doesn't find the damned network. the neighboring networks show up just fine, our home network still doesn't.

that ought to point towards a hardware defect, no?

 

Have you tried changing the name of the network (SSID).
Since you have another notebook to test it just swap wireless cards to cross-check it. That would confirm or rule out a hardware problem.

 

Does your SSID have other chr beside letters and numbers?