Thanks for your quick reply. Here are the details you mentioned which you have asked...
I use Windows 7 Home basic 64bit OEM copy.
I use Microsoft Virtual PC 2007 setup.
I installed windows xP from a CD into the virtual pc.
Total hard disk space is 320 GB. While installing WIN7 i did divided into 2partition. So total i have C: and D... I created the virtual hard drive of 3GB using my computer management as while installing it as asking for .vhd file. After installing the windows XP SP2 all i see the 3GB virtual hard drive space, the floopy drive and the CD/DVD drive. How can i see my actual c: or D: from the virtual machine.