hey Kuldip,
I feel your pain, as I have a Sony VAIO r505 laptop which I worked to get my linux running properly on (which now runs flawlessly).
Sony likes to be stupid and uses weird drivers for almost all of your hardware, so you will likely have to reinstall with just the normal XP cd, then go to the Sony Support site and download and install all of the drivers for your computer (like Display adapter, keyboard, mouse, network adapter, modem, etc etc). After that it should work fine.
Many Linux installers actually come with a disk formatter/partition editor so you can also use that. I managed to put both Fedora Core 2 and then Fedora Core 3 on my laptop without incident, as it seems Linux supports Sony products better than Windoze does (ironic considering Sony Help Line told me my laptop didnt even support windows Xp pro...stupid jerks).
But once you install the individual drivers from the sony support site (go through vaio.net) everything should work out fine, and then just use Disk Management Console in XP or the Linux installer's own disk partitioner to do the rest.
welcome to linux
