I have XP full version (not the upgrade) on my hard drive. I want to upgrade to a newer motherboard with a new processor and hard drive---BUT will be using my existing video card, modem card, etc. In essence, just exchanging the main items onto a new motherboard w/a larger drive.

I heard that XP "remembers" what motherboard you have as well as the cards, etc. I am concerned that XP will "look" at this change as a new operatring system due to the new hard drive, motherboard etc. and may not run. Is this true?

I think that when it boots up it will not "see" the list it has had as being complete, so it will ask to call Microsoft and have to pay some new"fee"?
The motherboard is a bit faster with a faster CPU. That is why the change.
Hope you can clear this up as to if I should do this or not.

There will probably be drivers that need to be installed. I would suggest that, first you check with the mobo manufacturer to make sure the mobo is supported by XP and that you have all the drivers you need.

You may need to boot first to your XP disk and do a reinstall (not a full reinstall, but an upgrade) top make sure the drivers work.

It is possible that XP will see this as a new machine and that you will need to reactivate XP, but that doesn't cost anything.