Windows 7 dual boot system with one xp key

I'm confused....

OK, let me see if I understand this:

a) You have a PC with TWO installations of XP in dual-boot mode.
b) You have a second PC where you want to create TWO installations of Win7.
c) You want to dual-boot XP and Win7...Where? Third PC?

I also don't get the part about how installing Windows 7 would cause your XP to stop working. And what does dual booting Win7 have to do with your one XP key, as per your post title?

Please try and explain yourself more clearly.

If you buy a Windows 7 Upgrade license, requiring you to enter the XP license number in order to install it, yes, you could have a problem with your XP dual boot machine, because you have informed the mother ship that you are now utilizing that license on a Windows 7 upgraded machine. The dual booting setup is a mute point here, the problem would arise from attempting to run xp on your old machine and the upgrades 7 on a different machine. That being said, it may work once, but then you may have a problem if you had to reload and activate the XP machine in the future.

I would wait and buy an OEM version of Windows 7 and avoid the issue altogether. Sorry if you already have it. You could try it once, just make sure you have image backups of your XP machine, in case you need to reload it later.

From what I can make out you have 2 computers one of which has XP, that you use for gaming and are concerned that by getting W7 upgrade, you will loose the use of that XP licence.
Why not get an OEM version of W7 which will probably cost around the same as the upgrade version, that way you get to keep using the XP computer without licence issues.

Thank you guys for the help,

To clarify, I have two separate physical computers, the one is my older computer, real sweet running lots of programs, XP on it, it is a dual boot setup, nice for a fast, non bloated gaming, or I can boot to my regular bloated system; So ok, I have my new computer with no operating system on it, I want to set it up just like my older computer, dual boot; Gaming and Work, I read somewhere that to setup a dual boot system with Windows 7, you can't activate the second boot up drive with a XP upgrade disk?? I love dual boot systems, apparently you can do it with a full edition Windows 7 disk, but I went and already bought a Win 7 Upgrade disk.

My other question is I have read that in the past Microsoft has not deactivated e.g.: my older computer which will still have XP on it, but other say that MS may deactivate the key on say your old XP disk, so you can't reinstall XP, although this makes sense, I can't see why or how MS could shut down my old XP, if I stop communicating with MS and if I have a problem, just have a up to date Ghost etc, image, then I can still run two physical systems?

Thank you guys for your input.

Thanks for your reply, ya, it sounds like you are right on the money, I'll just do backups of my XP in case of future trouble, as for the dual boot situation, I am going to look and try to find the information where other ran into trouble, intalling dual boot Win 7 with XP upgrade disk. I will post here when I find it.

Thanks again.

This sounds like an algebra problem.

solve for x.