OK...I guess you have unboatable image/Cd of windows XP and U want to install Windows XP with that.Here is how you can do:
1)Download BOOTCD from here
http://freepctech.com/files/xpbootcd.zip
2)Uncompress the CD,you will find a ISO file.Burn that IS file (that is bootable)..using Nero or may be anyother.
3)Boot with the Cd you created just now.
4)You will find some options..select the first one.
5)now swith to ur Cd drive in the installation
6)There do some work..like selecting the drive,formating(as usual windows installation).
7)Execute a utility called hdsetup so all the basic system files are transferred to the C: drive. This will make C: bootable and make the CDROM recognizable from the start.
8 )Reboot ur computer....log in BIOS..and change first boot device as HARD DISK.
9)Insert the Windows XP installation CD and right click on Cd drive and select OPEN.
10)Navigate to here Go to directory D:\i386, then type “winnt” to launch the install.(I suppose your D:/ drive is ur CD ROM drive)
11)And finally ur windows XP is installed.