see i've brought a new HCL laptop with having 250gb hard disk.......it was provided with ubunto os.......i later installed a fresh windows xp my deleting ubuntu from that partition and installed a fresh windows xp........but right now in my "my computer" only i can find c drive on which i've installed the windows.........can anyone help me please..........

Well, you deleted your Ubuntu partition when installing Windows, so naturally you only see one "drive" - the Windows partition identified as the "C" drive. So, what is the surprise/problem here?

I don't see any problem here like what rubberman said. You create a partition so you can install another OS or stuff on it when you delete the partitio all data on it naturally also get deleted. YOu install windows xp on your C drive partition that is why you can only see it unless you have other OS install on other partition but you cannot find them.

Right click on your "My Computer" and click manage from the list. Click storage then disk management then have a look at all partitions.
Post anything you see that you don't understand here and we will help further.