No wireless networks anymore

Attach a Ethernet cable to the laptop, Open Device Manager, Network Adapters, Uninstall the Wireless adapter, reboot, Allow the software to apply the generic driver, try to connect to wireless network. Post results.

Please install the latest wireless adapter card driver and then configure it to your wireless router.

Windows WiFi Fix,
Windows Zero Wireless Configuration is one of the best programs to run a WiFi in Windows XP or Vista. Most of the other software packages that come with the different adapters have been poor at best in keeping a connection through Windows. Here is the best guide to get you back up and connected.
Windows XP:
Click Start
Right click on My Computer
When a window pops up click on properties
Click on the Hardware tab
Click Device Manager
Click the [+] next to Network Adapters
Find your wireless card and right click on it.
Click Disable
Windows may warn you that disabling the device may make it stop functioning.
Continue disabling the device.
Wait 30 seconds or so.
Right click on your wireless again and click Enable.
Exit the device manager.
Reconnect to your router.
You should now be able to connect to the internet.

Windows Vista:

Click Start Logo
Right Click Computer
Click Device Manager
Windows will ask you about opening Device Manager Click Continue
Click the [+] next to Network Adapters
Find your wireless card and right click on it.
Click Disable
Windows may warn you that disabling the device may make it stop functioning.
Continue disabling the device.
Wait 30 seconds or so.
Right click on your wireless again and click Enable.
Exit the device manager.
Reconnect to your router.
You should now be able to connect to the internet.

try this...

Windows WiFi Fix,

Windows Zero Wireless Configuration is one of the best programs to run a WiFi in Windows XP or Vista. Most of the other software packages that come with the different adapters have been poor at best in keeping a connection through Windows. Here is the best guide to get you back up and connected.

Windows XP:

Click Start
Right click on My Computer
When a window pops up click on properties
Click on the Hardware tab
Click Device Manager
Click the [+] next to Network Adapters
Find your wireless card and right click on it.
Click Disable
Windows may warn you that disabling the device may make it stop functioning.
Continue disabling the device.
Wait 30 seconds or so.
Right click on your wireless again and click Enable.
Exit the device manager.
Reconnect to your router.
You should now be able to connect to the internet.

Windows Vista:

Click Start Logo
Right Click Computer
Click Device Manager
Windows will ask you about opening Device Manager Click Continue
Click the [+] next to Network Adapters
Find your wireless card and right click on it.
Click Disable
Windows may warn you that disabling the device may make it stop functioning.
Continue disabling the device.
Wait 30 seconds or so.
Right click on your wireless again and click Enable.
Exit the device manager.
Reconnect to your router.
You should now be able to connect to the internet.

Windows WiFi Fix,

Windows Zero Wireless Configuration is one of the best programs to run a WiFi in Windows XP or Vista. Most of the other software packages that come with the different adapters have been poor at best in keeping a connection through Windows. Here is the best guide to get you back up and connected.

Windows XP:

Click Start
Right click on My Computer
When a window pops up click on properties
Click on the Hardware tab
Click Device Manager
Click the [+] next to Network Adapters
Find your wireless card and right click on it.
Click Disable
Windows may warn you that disabling the device may make it stop functioning.
Continue disabling the device.
Wait 30 seconds or so.
Right click on your wireless again and click Enable.
Exit the device manager.
Reconnect to your router.
You should now be able to connect to the internet.

Windows Vista:

Click Start Logo
Right Click Computer
Click Device Manager
Windows will ask you about opening Device Manager Click Continue
Click the [+] next to Network Adapters
Find your wireless card and right click on it.
Click Disable
Windows may warn you that disabling the device may make it stop functioning.
Continue disabling the device.
Wait 30 seconds or so.
Right click on your wireless again and click Enable.
Exit the device manager.
Reconnect to your router.
You should now be able to connect to the internet.

The wireless driver may got corrupted or uninstalled.
Go to Control Panel - System - Hardware - Device Manager - Click on Network Adapters and if the wireless card is listed click on it to see if it is working and enabled. If not then reinstall the wireless driver.

TRY GOING TO START, START SEARCH TYPE WIRELSS DEVICE

LOOKE IN DEVICE MANAGE FOR WIRELESS FOLDER

INPUT DEVICES

AS SO CHECK THE FOLLOWING FOLDERS ALLOWING COMMUNICATION BETWEEN THE LABTOP AND THE WIRELESS DEVICE AND THE COMPUTER.

NETWORKING AND SHARING FOLDER
PROBLEMS AND REPORTING
SECURITY FOLDER
SYNC CENTER IF YOU HAVE ONE
WINDOWS DEFENDER
WINDOWS FIREWALL

THE LAST 2 PROGRAMS IN THE LIST ABOVE CAN STOP THE DEVICE FROM WORKING.
YOU WANT MORE HELP I WILL HELP YOU IF YOU HAVE THE SITE CONTACT RODGANDYSR@GMAIL

ROD

First thing is to check if the wireless device is working. Go to Control Panel - System - Hardware - Device Manager. Click on Network Adapters. Do you see the the Wireless card?
If not in Control Panel click on Network Connections, do you see a Wireless Connection? If not you need to install the correct wireless network driver, Check the IBM site again, there should be another wireless driver (there are a couple of different wireless card installed on T40 series ThinkPads).
THEN
If you succeed in installing the wireless driver and it is enabled.
Then click Control Panel - click on Network Connections - right click on the Wireless Networl Connection - Click on Properties and check if TCP/IP has been installed, if not install it. Check TCP/IP properties - make sure it is set to Obtain an address automatically and Obtain DNS Server address automatically.

Check the wireless settings on your other laptops, use this information to configure the wireless on the T43, ie the SSID, WEP or WAP settings

You should be able to connect to your wireless router and Internet now - let me know how it goes,

Kanasai, sounds like the wirless adaptor is turned off, normally this is the result of the power settings sutting it down on batteries to conserve power. you should have a FN key combination to turn it back on , for example on my ASUS its the "FN" key and the "F2" key at the same time.
Basicly you can check the device manager to see if the wireless adaptor is enabled. then look at what software manages the wirless connection

Make sure that there are NO electrical devices between you and the wireless router. Some electrical devices will mess your signal up.
(cordless phones are known to mess with them) too.
Microwaves interfere with the signal from your router. Interference means a low quality signal.
The following steps help you troubleshoot a bad wireless connection. Stop following the steps when the connection problem is solved:
1. Refresh the wireless connection that is giving you trouble.
2. Temporarily disable the firewall or Internet security software on the computer that is having connection troubles.
3. Open the wireless connection manager and make sure that the SSID is correct. Also make sure that encryption settings and keys match the settings in your WAP (Wireless Access Point).
4. Restart DHCP (Dynamic Host Control Protocol) on your WAP; if necessary reboot the WAP.
5. If the troublesome Wi-Fi adapter is removable - such as a USB, cardbus, or Ethernet bridge adapter - remove or disconnect it and disconnect any power cords. Then reconnect the device.
6. Right-click the My Computer icon in the Windows Start menu and choose Properties.
7. In the System Properties dialog box, click the Hardware tab and then click the Device Manager button (see Figure 1).
8. In the Device Manager window, click the plus-sign next to Network Adapters (see Figure 2).
If you see a yellow exclamation mark next to the name of the adapter, something is wrong. Right-click it and choose Uninstall, restart Windows, and then re-install the driver software as described in the manufacturer's instructions.