Other

Try the "Upgrade Advisor". If it's not on your XP CD, you can pick it up at:

http://www.microsoft.com/windowsxp/home/howtobuy/upgrading/advisor.asp

I have used the upgrade from Windows ME using the upgrade advisor,then during the install there was no report of any problems with photo shop which is installed on the machine.
It has been problems with anti-virus,modems,soundcard,and graphics adapters drivers that have been problems

PC pitstop www.pcpitstop.com has a tool that you can run to check for both hardware and software conflicts with XP.

Before you attempt to run any apps, be sure to go online and download at least the critical updates from Microsoft.

I would also check Adobe's site for any XP faq's or patches.

I have done upgrades using the Win2k upgrade and think that it better to back up files, do a fresh install and then reinstall files and programs. Otherwise sometimes you get programs stuck, where you can't uninstall or reinstall them but you can't use them either. Also I have seen performance issues that require prolonged time to diagnose and eliminate. So for my time I think it is better to start fresh without the stench of WinME.

You may want to consider holding off. Some of your devices may not working with XP because of the HAL (hardware Address List). There have been problems where the hardware is not compatible with XP.