Windows XP Activation Issue

I went to a friend to install a new DVD writer he had just bought into his pc. Removed his old cd writer, installed the new, booted up, detected correctly, as soon as windows loads it says it had a problem verifying the windows licence on the pc and says it will need to activate windows again. When we got this message, my friend told me microsoft office had given him a similar message since he had upgraded the ram( he had one stick of 256, added another of 512). I tried to activate but windows did not seem to recognize his internet connection anymore. Windows did not allow us to log on to the system before activating, so i could not access windows at all. ie. i could either activate successfully or log off/restart, i removed drive reinstalled old one, also removed all cd rom drives and left only hard disk, i also tried removing the additional ram he had installed, all scenarios gave the same problem. I then tried repairing the windows installation from the windows cd rom hoping it would solve the problem but after it reinstalled, the same message popped up. I am completely at a loss of what to do next about this problem. Help would be appreciated

 

Did you try activating over the phone? When the activation screen pops up, it should give you the choice of internet and phone activation.