hey guys,
I have a doubt that if I can install the windows XP along with Window Vista(which came pre installed in my lap) , without losing the Vista.(i.e. dual boot)
If yes ,How?
Please help guys!!!!!!!!

This is possible but you need to be very strong on Techincal Skills to proceed further with making a HDD dual OS where Vista is Already Installed follow below steps:

1) Take a Bootable Windows XP Cd and insert it in CD Rom drive .
2) select the version of XP you would like to install .(Server or Workstation)
3) click enter it will proceed with installation first it will detect system hardware devices and proceed with steps .
4) At one step you will see partitions .Always C drive will be the one wherein OS is already installed .
5) Leave C drive and select D or E drive through Up and Down arrows .
6) Once the drive is selected start and proceed with installation it will take not more than 45 minutes .It depends on Ram Size if it is 512 MB Ram then it will take 45 to 1 hour and if the Ram size is 1 GB then it will take around 30 minutes to complete installation.

Once the Installation is over now restart your system you can both Vista and Windows XP and your system will be Dual OS System.

Important last step

7. boot from Vista install dvd, and select repair installation(MBR in Vista is different from XP, and dual-boot won't work until MBR is repaired).

One very important point was missed out there. In order to dual boot you need 2 partitions, you cannot boot 2 windows operating systems from just 1 partition.

You need to shrink the partition with vista on it in "manage" then create a new partition on the free space and install XP onto that.

You will then need easybcd as suggested in order to sort the boot sectors out!

try to back up your data,, then have a fresh install,, install first the xp in the drive c,, then install the win vista to the drive d....

hope it will work for you....

try using Virtualbox download it from the net then read the instruction how to install win xp inside win vista