None Genuine Windows Xp

Hello people,

Friday one of our computers in the office came up with "you my be victim to counterfeited...bla bla" nothing to worry about, I just need some time and find the Windows license for that system.

The question is that the user has serious difficulty of connecting to Internet, sometimes can see the network and sometimes the whole network adapter is hidden in hardware manager, also the USB ports seem to work with the same frequency of sometimes work and sometimes not work...

I just booted the system with a Ubuntu Linux LiveCD and all hardware seem to work correctly, even Internet and networking works without a hitch. So is it possible that the source of all this mysterious device failures is to the not passing genuine Windows validation? I know it does that in Windows Vista... but never hear it with Windows XP.....