1. I don't think it should be a problem, since you can only run one version at a time. Each installation will require you to register so you don't run into the 90day limit.2. I don't know the disk size of the WinXP alone. I would think a 10-15-20GB partition would be sufficient for WinXP and Flight Simulator based on how many addons you intend to have. You also need space for a Windows SWAP file.3. Yes, when you boot, a DOS style screen will appear. The default time the screen appears is 30sec if I remember correctly. The problem will be that both instances of WinXP will have the same title at first. You can change the title under, Start, Control Panel, System, Advanced tab, Startup and Recovery Box, Settings button. At the System Startup and Recovery box, press the Edit button. Change on of the titles in the operating system section by placing a distinctive character after the title. Save the file, exit all menus, reboot your computer, and observe the two options available for booting. Pick one of the titles, and see if it loads the correct partition. If not, try the other one. You can also look at the partition information in the file you edited to see which partition is used for which install.4. No more than what you already know.W. Sieffert

If using NTFS the filesystem will perform best with a partition size of 20 GB or greater. If you install to a smaller partition than that there should be no problem. I'm just letting you know the size where NTFS is supposed to perform the best.Regards,Jim

As for 4: You might want to consider FS Autostart by Ken Salter. IMHO, the best tool to control services and not worry. It's more or less self-explinatory. Available here in the Avsim file library. Good luck and kind regards Jaap