Laptop with XP home- CD and DVD issues

We have a Laptop with XP home for a senior member of staff. He tried to install an external CD writer to his laptop but failed. The laptop see’s the external drive and the internal DVD drive but has a ‘!’ mark against them in device manager stating that the drivers are incorrect or corrupt. We would like to avoid a full restore if possible but we have to resolve the problem quickly. The drives have been removed from device manager and XP allowed to find them on restart. XP finds the drives, installs the drivers but the problem remains.