xp upgrade

It depends entirely on whether the manufacturers OEM cd is a true WinXP cd or whether it is a cd designed to upgrade just your hardware drivers and software for WinXP from Win2000, and whether it is a upgrade cd or a full-install cd. Most OEMs arenot full WinXP cds.

To be certain, you need to contact the manufacturer about what is on the cd and whether or not the cd they provided is designed to upgrade from Win2000 to WinXP.

http://support.microsoft.com/search/preview.aspx?scid=kb;en-us;Q311246

http://support.microsoft.com/search/preview.aspx?scid=kb;en-us;Q319424

There are postings around the net, on how to upgrade W95 to newer versions from an OEM CD.

You would need to go through a similar process of deleteing key files that windows uses.
No, I don't know whick files in W2K.

Alternately, you should be able to install XP along with W2K in a "dual-boot" arrangement.
Boot up the PC into Windows, and run the XP CD.

I assume that your goal is to maintain your installed programs, files and settings.
While I havn't tried this, there are 2 ways that you should be able to do this.

1. Get a second hard drive, set it up as your Primary Master drive, and install XP onto the drive.
Then, run the file and settings transfer wizzard, and point it to the W2K drive.

2. (More risky, as you need to get your drive to run in another PC)
Setup your existing drive in another PC, and install XP onto a new hard drive in your system.
Network the 2 PCs.
Invoke the file and settings transfer wizzard, and transfer the files from the old drive.

You will still need to re-install your applications.

Chas