XP doesn't do that. The yellow exclamation mark indicates there are driver conflicts occuring. There should be a driver CD that came with the CD.. If not, then clearly, your brother has a self-made CD with all the drivers downloaded? If he doesn't have that, the drivers for ALL the hardware will need to be found, downloaded and installed.. If no internet access from the problem computer, then you might be able to do it from a different computer and burn the drivers to a CD and transfer them over..

If the computer is a brand name computer, visit the manufacturer's website and check for the various drivers there.

For the internet, an ethernet driver may need to be installed.

Hope this helps.