I have fedora 13 on my system for some time. Now I need to install windows xp on this system so that I have dual boot system which means when I restart the pc, I am shown a screen (by fedora) in which I have to choose whether I want to boot to win xp or fedora. By default it should boot to fedora if I dont do anything after lapse of some time.

I know how to do above if I install windows xp first and then fedora.
But unfortunately I already have fedora installed and I cannot remove fedora and re-install.
I tried to find the solution by googling but nothing helpful came up as almost every time it talks about instaling linux after windows xp is installed which is comparatively piece of cake.

I also already setup windows as virtual guest os in fedora but I also need to install windows natively on the same system.

I know there must be a way to do that. So I hope some one can help.

I've never installed windows after linux, so, take my advice with a grain of salt. you've been warned!

In order to do this, I think you'll have to reinstall grub (the fedora boot-loader) after you install windows, because the windows bootloader doesn't like to share, and will take over the MBR.
also, you'll probably want to partition your hard drive in advance, and make a NTFS partition for windows to live on (I'd recommend gparted) if you haven't done so already.

this from the fedora forums might be useful, also:
http://forums.fedoraforum.org/showthread.php?t=206216

It's a tad outdated but it should still help, and it shows you how to fix grub after you get windows running

I have to say, though, that it might be easier to backup your /home and just reinstall fedora after you get windows running.

hope this helps!

Run fdisk -l to get your partition information if you do not know it so you do not install xp over your Fedora. Instructions on how to do this are at the site linked below. It references Ubuntu but the steps should be the same:

http://apcmag.com/how_to_dual_boot_l...lled_first.htm

At least in theory, the NTLoader form Windows is not that much different than Grub or Lilo. I have never tried this nor would suggest it, but I did find an article on this.

How to dual-boot Windows NT/2000/XP and Linux using NTLDR
http://jaeger.morpheus.net/linux/ntldr.php

One suggestion I might from when I very first learned to make dual boots. If you re-size the partitions, then you should be able to make a tiny FAT partition so that both Windows and Linux can share the same mount to boot from. Then use that as the mount for Grub / Lilo.