You'll be able to read from/write to the old ME drive, but there won't be booting conflicts or the like with XP, if that's what you're concerned about.
DMR
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Sounds like you've got it covered; I can't think of anything else:
* Set BIOS boot order.
* Install new drive as the Primary Master dirve.
* Install XP and make sure everything is working properly.
* Reinstall old drive as a slave drive.
As you indicated, you should leave the old drive out of the system until you've verified that the XP side of things is working. When you do reinstall the old drive, just make sure to pay attention to the Master/Slave jumper settings on your devices.
DMR
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Sounds like you're good to go. Late in life, the 4100 systems shipped with XP, but I don't know if there was a BIOS upgrade that needed to be done or not.
alc6379
Cookie... That's it
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