Installed XP over windows 7 no internet?

The next is the problem with installing WinXP on new hardware is the drivers may not be available for WinXP. Many hardware manufacturers did not bother with WinXP drivers for the new hardware because they are designed for Windows 7. So the smartest thing to do is reinstall Windows 7 from the Recovery Partition or the Recovery DVD set. The yellow icons represent missing drivers for those hardware components. If you insist on keeping WinXP, then I am sure someone, somewhere has done it. Sure the net for instructions and drivers.

the devices shown in Device Manager and find the drivers for them.

I'm going to say the best thing to do here, assuming your son didn't wipe out the recovery partition in the process, is just to reinstall Windows 7. Then rather than discourage this sort of thing, maybe look around for a used computer that he can do whatever he wants with so it doesn't affect your computer.

Of course another reason to reinstall Windows 7, is that odds are that copy of XP is pirated. You can still find the odd OEM copy around if you look, but XP hasn't been for sale officially for quite some time, so unless you guys had a copy floating around somewhere from an older system, the safest bet would be to assume it's a pirated copy and that is definitely something you want to discourage your son from doing. Whether or not you give a flying flip about the morality of the issue, it can have some nasty legal consequences down the road.