When a client brought me a laptop last week that would no longer connect to the internet, I suspected another case of 'dead router syndrome'. Having had a case of this myself recently it would have fitted nicely - Windows could no longer see the network over wireless and the Ethernet connection had dropped from solid, to patchy, to nothing over a few days.
On bringing the laptop back to base, it was clear that the router was blameless as my two 'known good' connections had none of it. It also failed to install any new hardware I put its way, including a 3G dongle. Reinstalling /patching the network adaptor drivers made the situation worse with drivers failing to install.
Puzzled and with the client keen to get their machine back, I went for the 'cop out option' of re-installing Windows. I hate doing this as it always feels that eats up the client's time in getting their system back the way they like it. However, in this case as the machine was used solely as an Internet terminal and almost box-fresh in its set-up it was not too much of a problem.
Result - a happy client with a machine that went straight back on the 'net as soon as Windows installed and I'd even managed to remove some freeware that had been causing issues!
Give me a call if you have a Windows PC giving you problems