oh where, oh where has my wi-re-less gone...

It just stopped connecting, or you re-installed Windows and haven't been able to get a connection since?

 

Shouldn't really be any setting. Detect the network, tell it to connect, and if your network is encrypted it asks for the WPA passphrase or WEP hex key.

If it was a Windows repair install, it would probably be a good idea to reinstall the wireless adapter/utility.

Are you using the adapter's utility or Windows XP's WZC, and was that the one you used before the reinstall?

If installing the adapter was part of the Windows install, are you using the same driver (not an older one) as you were before?

Sorry for the disjointed suggestions, but you haven't really given much to go on yet.

 

"I presume the driver is the same post re-install. How can I ascertain?"

Unless you are positive that you (or stepbrother) never updated the driver, it would be a good idea to check for the latest driver on your laptop manufacturer's web site.

There should be no need to be messin' around with network authentication settings, unless you've messed it up. You start out with it "open" and when you get a connection it will be changed automatically if needed. Your problem could well be that your current driver does not support WPA, so let me make a stronger suggestion to go looking for a driver update.

You access your router via browser on (preferably) an ethernet connected computer. See the User Guide for default IP, user and password if they haven't been changed. If you do an ipconfig /all the Gateway address is the router's current address.

 

"but that option does not let me 'enable IEEE authentification... ' ."

Good! Typically when that gets set erroneously the connection drops within minutes because our home routers do not support it. Some large businesses have the equipment needed to use that.

 

Unless you are copying very large files across your LAN or have a pretty weak signal I wouldn't expect you to detect the small decrease in speed caused by encryption.

To resume WPA, logon to your router using an ethernet connected computer, find the wireless section, and enable WPA-PSK (may be labeled security instead of encryption). Then again connect your wireless computer(s) using the same passphrase.