Win XP Pro OEM vs. Full Retail

Can someone help me out with this. I keep reading that an OEM copy can only be "tied" or "licensed" to one machine, so that upgrading, past a certain point, is not allowed. However, if I own the "full" or "retail" version, I can move that license from any one computer to another as many times as I want, providing of course that I don't attempt to run both computers at once. Does that sound correct? Or does Microsoft allow people to move OEM licenses in the same manner? My primary concern is upgrading. If I want to move from a 478 P4 to a 775 Dual Core, just about all the hardware is going to be substantially different, and I am sure I would exceed the number of points that can be changed and trigger a re-activation requirement. I'm not trying to do anything illegal, I just want to know what licensed I need up front so I don't have to keep buying OEM licenses every time I upgrade. Thanks for any help.

You are quite correct.

If you plan on doing lots of upgrading, then the retail version of Windows xp is the way to go.

Regards Howard

Thank you for your reply. That is what I suspected, and I have no problem paying the extra money to be able to do that legally.

I have to partially disagree howard. It really depends on the make and manufactuer to the OEM CD. (Although in most cases upgrading an OEM machine - like laptops is limited anyway so the point is moot.)

I've been thorugh this.

Yes, you can change hardware on an OEM cd. If you Change it signifiacntly and you have to re-activate, you have to call in to microsoft and they will give you a new activation code.

OEM is different from retail because OEM cd version:

-Comes in a envelope instead of a nice blue box and has no manual.
-Has no support. You have to pay to get support ( except activation centers which are free)
-You cant return OEM versions at all or get refunds at all.
-Cant install on an existing operating system. You have to reformat and do a clean install. You can however reinstall on the same OEM copy.
(e.g. installing windows XP pro OEM on windows 2000 pro will be unsuccesful)

you can't change the motherboard and some oems are not upgradable as far as service packs go
stick with retail or learn linux

OK, well, the OEM copy is one purchased from a .com store where I bought the CPU, MB, etc. so I am not trying to take a Dell or HP OEM license and put it on my plain vanilla system. That's what I am wondering about. Can I move an OEM copy of XP Pro from system to new system. I don't need support and I am not concerned about having to install clean, etc.

Thanks again for any thoughts on the matter.