If you are in the US and qualify you can get the Windows XP disc ("backup discs") from Dell   Click Me

If this is a Dell OEM disc that is broken, only another Dell OEM disc of the same version will work with the Dell product key.

Thanks fireberd fro reply, but I want .iso bootable official direct link

There is no such thing for XP.  The only "official" and "direct" ISO's for XP are found as part of a Microsoft TechNet or MSDN account.

Unfortunately there isn't one, hence I was unable to make a wiki. XP wasn't sold by digital river and there is no official retail .iso without purchasing a technet license.

In addition Microsoft is trying to phase out Windows XP, its support will end in 2014. All I can advise is to buy one of eBay or borrow a friends of the same version (Home, Professional or Media Centre Edition), the Service Pack on the disc doesn't matter too much, you can easily update it and create a .iso following my wiki Upgrade your Dell XP Reinstallation Disc with Service Pack 3, Internet Explorer 8 and Windows Media player 11.

Note your disc, you say is "broken" how broken is broken? I mean is it just scratched or is it snapped in two?

If it is scratched, then you might be able to copy it using a newer desktop or laptop (they often can read scratched CDs and DVDs that older systems can't) again following the steps in Upgrade your Dell XP Reinstallation Disc with Service Pack 3, Internet Explorer 8 and Windows Media player 11.

If your system is an older one and can't read the CD due to light scratches then it might be worthwhile making multiple copies of the CD. I done this when performing a clean install of Windows XP on an Optiplex 260 and a Precision 360. During the Windows installation, at the copying files stage it said it couldn't find some files, they were all there but the system couldn't read the CD very well, probably some angles/areas it has troubles with. I made 3 CDs; it couldn't file a certain file on disc 1 so I swapped for disc 2 then it couldn't file a file on disc 2 and then I put disc 1 back in and kept iterating the process between the 3 CDs until it had copied all the files.