A friend of mine gave me a computer - not bad; 2GHz, enough ram, enough HD space, etc. for what I want to use it for (utility standby, mostly). Unfortunately, it came with XP Home and I'll need XP Pro.

I see on eBay people selling the COA stickers from "decommissioned computers". What exactly does this mean? I have an older PC in the basement running XP Pro that is not strong enough any more - can I "decommission" this computer and re-use the COA? Would that mean if I ever use the old PC on line Microsoft's security police will come knocking?

I have the software and a valid license. I just want to transfer it to another machine. I know it's possible because I went through it before but I've forgotten exactly how I did it.

Any help appreciated.

Legally, no. The problem is that they are OEM licenses--tied to the hardware.

I'm pretty sure that moving the license from one computer to another is verboten, so the new computer will probably have you call Microsoft when you try to activate Windows. Just tell them that you replaced your hard drive and motherboard.

Or, better yet, install Ubuntu Linux. It's free and much faster than XP. You can do with Ubuntu all the things that you can do with XP - documents, spreadsheets, web, email, multimedia, etc.

If you purchase a RETAIL version of a Microsoft OS you generally have rights to TRANSFER that license to another machine. That and getting support directly from Microsoft are really the major differences between an OEM and a retail license (and $100 or so).

So, if that box was from Dell, HP, etc, it probably has an OEM license and Microsoft could (but likely would not) deny you an activation. If that was a homebuilt PC and the builder bought a retail version of the OS from a store you are within you rights to move that license and get a activation code.

Either way, its unlikely you would be denied an activation code unless you have installed that same license many times.

Something to keep in mind--since it's not legal that means you're dealing with cheaters. Not exactly the sort of person you want to deal with.

But what would be the downside for me? And I mean direct financial impact.

As long as your XP Pro license is a RETAIL or UPGRADE licence, youi just need to start the install and call Microsoft for an activation code. With a RETAIL or UPGRADE license just tell the rep you are installing on a new machine and have removed the software from the old machine and they should give you an activation code with no difficulty.

If you have an OEM license that is tied to that motherboard, you can call and likely will get an activation; the odds of the SPA stopping by to check that out is close to zero. So the direct financial impact of reusing an OEM license is probably zero, however such a use is clearly NOT within the terms of the license. Up to the OP to decide if he/she is willing to violate that agreement however one-sided it may be.

I haven't looked at this for a few years, but the last time that I did, there was a split of authority as to whether Microsoft's license scheme violated First Sale Doctrine. I'm not providing an opinion either way, but I wouldn't assume that, just because a license says something, it's necessarily enforceable at law.

Depending on how tied you are to Windows, you could also always install Ubuntu Linux (www.ubuntu.com). Linux runs faster on older machines and Ubuntu can do everything that Windows can. Ubuntu is a flavor of Linux that is designed to "just work" out of the box.

Ubuntu is 100% free, like all Linux.

I'll agree with that. Believe oem coa's (technically) are licenses tied to that specific cpu. When the hardware dies, so does the liscense.

A very vaild point. But even if the legality on installing an OEM license is in question, nothing would oblige Microsoft to provide an activation code, and without that one could have legal, but useless software.

Cheers