Hi I have Lenovo laptop. It was with windows Vista, but i downgrated to windows XP. I had problems with the wireless driver, but everythig was ok when I installed broadcom 802.11g network adapter. (the Lenovo care program downloaded and fixed for me). My internet connection was working for a little while and then stopped. I restarted my laptop and I am not able to connect anymore. The computer tells me that one or more wireless networks are available - but it also says that wireless connection is unavailable. I uninstalled and the installed the broadcom 802.11g network adapter again but no result. My cable connection is working fine. I know that the problem is NOT in the router I have (it's Belkin anyway), as there are some more laptops connected to the same one and they are working fine. So I don't know what the problem is.
Thank you for your help.

Let's start with the router anyway, eh?
If you are the manager of the router, can you check if someone activated MAC filtering and only lets certain people on (usually in advanced settings).  I would also check if the router ran out of IP addresses in its pool (happens with Netgear routers way too often).

If that's not the case, Lenovo had its own little wireless utility Function+F5 key, I think.  See if it brings up a little menu with your wireless devices such as bluetooth and wireless network card.  Make sure your wireless card shows as "on".  

There's also Lenovo's proprietary "connection center" or something along those lines which can manage your wireless connections, but it may also stop you from connecting to the network.  If you're using it, see if you would be able to connect by using windows' native wireless network manager.  If not, see if you can connect by using it.

I would also suggest to troll through Lenovo's forums - they have some more information on troubleshooting wireless issues.

Please follow up with resolution to your problem to help others here.


thanks,
Tom