Question : Lost restore install disks. What do I do? Laptop has genuine XP sticker and serial number.

A client would like to clean up their work laptop and restore to factory settings. The machine has XP Pro installed. They do not have the original XP install cd or the restore cds from dell. The machine does have a genuine XP serial number and code sticker on the bottom. What can I do to reload windows XP on the machine?

Answer : Lost restore install disks. What do I do? Laptop has genuine XP sticker and serial number.

Getting recovery CDs from manufacturer is probably the best bet.

Additionally, check to see if there is a recovery partition already on the hard drive. With drive sizes these days most manufacturers actually put an image of the recovery CD on the hard disk that you simply boot into by choosing F8 at boot time which does the same thing as the CDs.

But you can install from a CD containing the same specific version of XP. By that I mean that if the original OS is SP1 or SP2 and is an OEM version, Volume license or Retail, ect... Then you need the actual 16 digit "Key" which is not generally what you see on the sticker but is typically on the CD or the CD packaging. If you do not have the key written down somewhere then to get the Key you need something like MagicJellyBean to extract it from the current system. Once you have that you just need to borrow the specific CD I mentioned earlier.
Or, as SheharyaarSaahil stated, you buy a new copy of the OS.