How To Install Windows 7 Without DVD,USB Device,Network or Any Other External Device.
When To Use Thing Method:
  1. You Dont Want To Waste Another DVD
  2. You Dont Have a USB Hardisk
  3. You Dont Have a USB Pendrive
  4. You Dont Know How to Boot Windows 7 using the PXE Network Option

Here's How:
  1. Unrar the Downloaded ISO to a Partition on which you are not going to Install Windows 7.
  2. Make sure you have around 8GB of free space on the partition you wish to install Windows 7.
  3. Go to the folder where the ISO is extracted.
  4. Run Setup.exe and Follow the instructions.
  5. The installation Runs Like Usual.
  6. If you installed windows on a partition where another version of windows was already installed, Just Delete the Windows.Old Folder.
  7. You have a new build of Windows.
Pros:
  1. No Technical Knowledge Required. Just Extract And Start Installing. :D
Cons:
  1. You cannot format the partition where you are installing windows.
  2. You cannot change the size of partitions.

Hope this helps many people as i searched Google alot but had to figure this out by myself.

Regards,
Abhimanyu.