Remove Vista from Windows7 PC

Hello friends,
I you guys will help me then i will be very grateful. I have installed the Windows7 Operating system on my computer system. Previously i was using the Windows Vista operating system in my computer. But i was not having the enough space to install the Windows7 in C drive of my computer. So , i installed it in E drive. But now when i start the system the option for selecting the Operating system from these two appears on the screen. I want to delete the Windows Vista operating system from my system to get rid of this problem. How can i do it?
Hoping reply from you guys as soon as possible.

Right click on the C drive and format it.
After formatting the C Drive restart the computer. If you are getting that the MTLDR file problem, this means that the boot entry C Drive is deleted.
You follow this steps to reconnect boot system
1- Insert the Windows 7 Disc and restart the computer for booting from Disc
2- Press any key to boot from Disc , Enter or the space bar for Windows Recovery
3- Click on Next and after that click on Repair computer.
4- Select the problem related to Windows 7 and press Next

You are currently having two operating systems in your computer. You want to delete the Windows Vista OS and want to keep Windows7 operating system. You have installed the Windows7 in drive E and Windows Vista on the Drive C. You want to delete the Windows Vista installed on Drive C. To do that you will have to reinstall the Windows7 on the drive C. Insert the Windows7 Disc in the Rom and restart the system. Boot it from the disc. afterwords you will get the message this system is already having the Windows Vista operating system. You will get some choices over there. Select format the C Drive from there. This will install the Windows7 on your system and will delete the Vista from the C Drive. However to remove the existing Windows7 from your system Format the Drive E also.

If you are not able to do this by yourself then i will advice you that you should not do this by yourself. Call up the computer engineer or contact to the computer repairing center . They will properly solve your problem. They will charge you for this. Normally they charge around the 500-1000 rupees. But your computer will be safe. If you will try to do it yourself then there is the possibility that you can make some mistakes and it will affect your computer system.