Weird network problem

[*brammie*]

Hey guys! long time no see

A friend of mine asked me today to fix her internet, as it suddenly didn't work anymore.
So, I tried to restart her router, to switch the connectors, to reinstall the drivers, but it all did not work.
Final conclusion: i had to reinstall windows, so i deleted vista and installed windows 7.
well, that didn't work too.
The next thing i tried was to connect using a wifi usb stick, but without succes. (i'm sure the stick isn't broken)
and that's where i gave up.

some details: using the LAN, it claims to have "local acces", but i think that's a lie.
using the wifi it wouldn't even connect (it's abled to see the router). My iPod touch works perfectly on the same router. (yes i checked the password a 100 times)

anyone knows what to do

[FrozenKnight]

Ok *brammie* i think i need to explain a few things about how the internet works. From what you described it sounds like your treating her router as though it's a modem. a router only routes the signal from the modem to a sub-network, often refereed as a LAN "Local Area Network". So when the computer reports local "local acces" this means the computer thinks it has a network connection to the LAN. A way to test this is to ping the router, if it has a good connection then the router should respond to the ping.
if the loss of the ping is 0%, as i suspect, then you need to check the routers connection to the modem and that is router specific.

Now other possible scenarios are that the Wifi may be connected but the computer may have been setup incorrectly. Such as the router requires that you use Dynamic Ip and the computer has a static ip, or the router may be set up only to allow specified MAC addresses (All lan cards have one cards), I've seen this before and it can be a pain in the *** to fix. (this can be caused by the person accidentally adding there mac address to a blocked list in the router or removing their ip address from the allowed list in the router).
Another possibility is that the Wifi card is over heating, heating a Wifi card too much can cause it to slip slightly out of the desired frequency 2.4GHz (Sometimes permanently requiring the card to be replaced.) this sounds like the most probable case. and it can occur suddenly and can be hard to track down. pinging the router (if you can make a connection is the best way to tell if this is happening, if you are close to the router have a strong connection and yet still get a high loss percent then this is probably the case and you will probably need to replace the Wifi card.) the bad thing is that if the over heating isn't caused by a defect in the Wifi card the problem will most likely re occur, so this may require additional problem solving, note this happened to my Wife's laptop once, and every wifi card we put in it worked while the laptop was cool and not when it was hot, one card was even permanently damaged.
There are also a lot of other potential problems, such as another Wifi device may be causing interference with her router (blue-tooth, microwaves, and many cordless phones, and even some lamps also operate in the 2.4 GHz range) this can sometimes be solved by simply changing the routers channel.

[*brammie*]

whoa! that's a long story.. one little detail: it's a router and modem in one
I think i have enough information to fix it now

[FrozenKnight]

If it's a router and modem in one then there may be a few other things to check. If the router is set to get DCHP from the ISP and pass it directly to devices then you may have a case where someone is stealing her internet and that because of a limit on the number of assignable IP's the person stealing the internet may have the sole IP reserved for her computer. So you might want to check for that. This may allow a LAN connection but she would never get an I.P. address. So it might help to check the DCHP settings on the router, maybe even something as simple as changing the password might fix the problem, if you do this i would recommend using AES encryption it's much harder to break than WEP.

There are a lot of other causes as well. I'm glad at least some of my ranting has helped you

[*brammie*]

w00t!!

changed the password and that worked
Thanks man