Although the installation time of any Operating System also depends upon installation media and the drive performance, you can reduce your installations time up to 1/3rd. I was tested it on five computers and the installation time on different computers are varies from 9 minutes to 13 minutes. 9 minutes in best case and 13 minute in worst case.This is the fastest installation of Windows Xp. Now let us proceed.
Step 1: Start your Xp installation as usual, that is insert your bootable media (cd or pen drive / flash drive) and Restart your Computer.
Step 2: After the computer is booted, do all thing exactly same as you done in general Installations. That is select your Drive in which Xp to be installed, and then format the Drive in NTFS file system if needed and proceed.
Step 3: Now Windows will copy the files and Restart for 1st time automatically.
Step 4: After the Restart, computer will begin installation and you will see, ‘setup will completed in approximately: 39 minutes’ on installation window shown below. 
***Step 5: At that instant press Shift + F10 and you will see that the command prompt is open (if not then try again after 30sec.). Now in command prompt type taskmgr and press Enter, then the Task Manager is open.
***Step 6: In Task Manager go to processes tab and Right Click on Setup.exe Then in that menu go to set priority and set the priority to High by clicking on High. Shown in screen shoot given below. 
Step 7: Now you have done, close the Task Manager and Command Window and continue as general installation.It will take exactly 9 minutes from now.
You can also apply this trick on Windows Vista or Windows 7 but it is not required because windows vista and windows 7 by default take very less time to install. If you have face any problems during this process just mention in comments.
