There is a flat text file on the OEM disk with the install script, this is where the OEM key is. If it doesn't match one of the BIOS outputs, the install won't activate. OEM just pre-activates the install. Even if you use a different OEM disk, you can change the key to the COA sticker and then activate as a "retail" version (which will most likely spit a 1-800 number you will need to call). Or, do one of these reinstall:
1. XP is old enough, you could probably google the model of the laptop and find what key that script should have in it and burn a new OEM XP MCE disk with nLite placing the proper OEM key into the field. nLite has enough documentation to walk you through this.
2. Stop using the OEM, install a retail XP MCE version instead and use the COA sticker key. You will need to follow up, mostly likely, with a phone call to a 1-800 number. No big deal: you lost the recover disk, the partition is not recovering the OS, and you reinstalled. You can create a retail version also using nLite and burn to a new disk.--
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