I had a bit of a problem with a restored computer where the CD drives would not appear in My Computer in Windows XP.
After a little bit of grief, I found that the problem was a simple registry setting: http://www.siliconguide.com/qa/forum/messages/71.shtml
To resolve the issue

Open up the registry editor (Start > Run > regedit and click ‘OK’)
Navigate [...]

A neat trick I picked up while browsing t’internet is how to carry out a quick motherboard replacement on 2000 or XP Windows systems:
Before you swap out the current motherboard go to device manager and select the IDE ATA/ATAPI Controller and select your current storage controller. Right click, select update driver and select install from [...]