Longer answer. Maybe, it depends.
If either computer is a brand name (OEM like Dell, Toshiba, HP/Compaq...) that negotiates branded versions of XP with microsoft, you may need the OEM disk to install without buying a generic OEM or retail license key. The oem disk is autoactivated and does not require a cd-key if it detects the correct bios, model number or hash that the oem disk is limited by.
If they are white box or system builder computers from your local computer store or one you built from parts, the the OEM generic xp you bought with the system has a COA that should work with any other generic oem xp install as long as the disk matches the version (home or pro)
Replacement oem install or recovery disks are available for a small fee from most OEM vendors. Post the service tag, serial number or part number if you have a brand name computer and we can point you to the right place to order the disks.
I just spotted the last line of your post.
Sony usually does not offer anything helpful unless you are still under warranty, but you can try:http://esupport.sony.com/EN/osmig/xpclean.html
Gateway varies. If you get an unintelligible idiot, just hang up and call back:http://support.gateway.com/s/software/medi...age01su44.shtml
Edited by Ken-in-West-Seattle, 05 May 2010 - 06:20 PM.