Windows 7 operating system how to format C drive

I originally used XP installed in the C drive, is FAT32 format and now installed a Windows7 on the E drive now I want to put the C drive to install Windows7 in C, However, I found out that Windows XP has been deleted before I can't find it. But now I can't install Windows 7 in C. How can I ask? Have a Windows 7 installation tool and CD-ROM installation to extract the image to the root directory of the D drive or D drive and then run the Windows 7 installation tool to restart the computer into the installation interface to format the C drive and then choose to install to the C drive and CD-ROM installation exactly the same tool you want Can be sent to you. There is also that you do not re-install the system to go to the C disk. You can not enter the Windows 7 boot file. Windows 7 boot file more on the main disk C disk DE disk how much logical disk you now choose 2, re-install the system grid The C drive installed the system C drive; Second, keep the C drive to maintain the current state.