It would really depend on the machine you are using. If it has an x86-compatible processor, probably. Otherwise, no. The ASUS Eee PC would be an example of a device that often comes with Linux, but can run Windows as well. A cell phone or PDA would be an example of a device that this would probably not be possible for.
There is no such thing as "Linux XP". If you're referring to Windows XP, then the answer is no. As far as Linux distributions, for the majority of distributions, they are free (as in freedom) and free-of-charge.
Linux XP is a shareware Linux distribution which seeks to offer a user interface similar to Microsoft Windows XP. Unlike most Linux operating systems, Linux XP is offered as a 30-day trial after which the OS will disable itself until it is registered. It is currently owned and being developed by the Trustverse company based in Moscow, Russia.
Before you format xp you will need to go onto Linux and create a grub boot disk by typing grub-install /dev/fd0. This will create a floppy disk which you can use to start Linux after you have removed and reinstalled xp. After removing and reinstalling xp use the disk to get back onto Linux and use grub-install /dev/hda to restore the Linux boot screen.
Make sure that you have installed the Samba client package on your system.
Yes.
Yes. All you have to do is give Linux its own partition.
Buy and boot from a Windows XP cd.
Windows XP is not in the direct upgrade path of Red Hat Linux 8.0. If you want to install Windows XP on a computer / server with RHL, you need to check the hardware specifications to see if Windows XP supports it.
Yes.
windows xp ,linux,vista
Use the ON/OFF switch. If XP has trouble with protecting data integrity under those conditions, then consider switching to a modern OS like Debian Linux which comes bundled with robust journaling filesystems.
Yes. You can switch back and forth by changing the boot order of the drives in the BIOS.