My system is dual boot XP and ME. If you dual boot, you'll have to reinstall some apps while running the new operating system to get the registry entries correct. I just reinstall over the old installation, and it seems to work pretty well. Really though, unless you've got a piece of hardware the XP doesn't support, or a software that won't work correctly in XP, you should just upgrade. The cost of running 2 systems in disc space is a pain. After a while the dual boot screen starts to be annoying too.