If you have a system originally built by a large OEM and you can’t find the original disks that came with it. With Windows XP, the installation media for this type of system uses a technology called System Locked Preinstallation (SLP) to prevent its use on a system other than the one it came with one from the same manufacturer and the same product family. The good news is that you don’t have to enter a product key or activate an SLP system. The bad news is that if you lose the CD that came with your system, you’re out of luck.
Or at least you were. Check out this Dell Support page, that has been around:
Dell Customers can now request a set of backup discs containing the factory-installed operating system as well as the device drivers and utilities specific to your system.
Requests are limited to one (1) set of backup discs per system purchased.
The backup discs requested must match the operating system that was factory installed on the original order.
Please note that Dell will provide you the most up to date Resource disc available, containing the latest drivers and diagnostic tools currently being shipped on new systems. Due to the frequent updates, this Resource disc may not have all the drivers needed for your specific system, especially if it is over one (1) year old.
Source:→ Ed Bott'sMicrosoft, Windows, Windows XP, Dell, OEM, Support, OEM disks