How to format the C drive in windows7?

I used XP installed on the C drive, it is FAT32 format and now installed a Windows7 system on the E drive. Now I want to put the C drive in Windows C, but I found the grid after I deleted Windows XP. No... but now I can't install Windows 7 in C. How do I get it?
There is a Windows 7 installation tool and CD installation. Unzip the image to the root directory of the D or D drive and run the Windows 7 installation tool. Restart the computer and enter the installation interface to format the C drive and then choose to install to the C drive and the CD is installed exactly the same as you want the tool to send to you.
There is that you do not re-install the system to go to the C disk. You can not enter Windows 7 boot file. Windows 7 boot disk file more on the main disk C disk DE disk how many logical disks you now choose 2, one again Install the system grid C drive to install the system C drive; Second, keep the C drive to maintain the current xp system download.