Ok guys as promised earlier.....here is the method using the Linux System Rescue CD.....
unfortunately i am not able to edit my posts.....so i am posting here in reply.......or i was planning to put it in the first post by using edit...
So far in our series we've covered how to reset your Windows password with the Ultimate Boot CD, but if you are a little more technical you might want to simply use the excellent System Rescue CD, which is based on Linux
Creating the System Rescue CD
Before you can do anything else, you'll need to download a copy of the System Rescue CD from here
Code:
http://www.sysresccd.org/Main_Page
now burn the ISO image using Imgburn.
now the main thing.......Resetting Your Password
Now that you have your boot CD, you'll want to boot from it, which will take you to this very informative prompt, with some basic instructions on how to use the CD.

The first thing we'll want to do is mount the hard drive, using this command. (Note that you might not need to use the –o force argument, it's only really for when the system didn't shut down correctly)
ntfs-3g /dev/sda1 /mnt/windows –o force
You can use the df –m command to verify that the drive has been mounted and that it's the right drive. Note that it's mounted on /mnt/windows at this point.

Now you'll want to change directory into the Windows/System32/config directory inside of your windows installation. For mine, the full path was something like this, but it might be different on yours:
cd /mnt/windows/Windows/System32/config
Once you are in that directory, you should see that there is a SAM file, which is where we'll want to change the passwords.

To change the password we'll use the chntpw command, and it's most useful to use the –l argument first to list out all the usernames in the file.

Now you can add the –u argument with your username, which will end up being something like this command, except you'll want to replace geek with your username:
This will present you with a wizard type screen:

I'm going to assume that you want to set a new password, so just type "2″ at the prompt, add in your password, and remember to use the "y" key when prompted to save

At this point your password has been changed, so you can issue the reboot command to restart the computer (should take the disc out of the drive)

And now you should be able to login with the new password. Note that this technique on both XP and Vista with good results.
PS : use this method only if ur a tech geek. this is kind of complex method if u dont know abt linux. but its definitely a great thing to learn