You need to check with your chosen manufacturer or supplier as to what is provided. There are variations:
- Recovery disc with full WinXP supplied
- Recovery disc an option to burn yourself from preinstalled WinXP
- Driver CDs provided
- You are required to burn a CD with drivers from preinstalled folder
Finally any recovery or restore CD - ask directly as to whether full WinXp is on it and whether you can use this to make a clean install. OEM (Original Equipment Manufacturer)versions will restrict you to the PC that it came with. Have alook at other threads which explain further re OEM.