Sometimes when you add things to XP, the installation files are needed. XP will prompt for the installation CD. To facilitate the process, you can copy the i386 folder on the CD to you local hard drive and change the registry, so that XP will look for them automatically

Edit these 2 keys
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion
In SourcePath, change the value to the correct i386 folder (eg. e:\i386 to c:\i386)

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup
In SourcePath, change to the correct drive letter