windows 7 - Why can't I install win7 64 from hard disk?

My system is Windows XP, I want to install the 64 bit version of Win7 from hard disk.
1. I downloaded grub4dos and extracted files into the C: disk, copied win7.iso into the C: disk.
2. Edited boot.ini as the following:

[boot loader]
[operating systems]
c:\grldr.mbr="Grub4dos"

3. Edited menu.lst as the following

   
   

   title install win7
   find --set-root /win7.iso map /win7.iso (0xff) || map --mem /win7.iso (0xff)
   map --hook
   chainloader (0xff)
   savedefault --wait=10

When I reboot and enter into installation, click install and next, I get these errors:

No device drivers were found, make sure that the installation media contains the correct drivers, and then click ok.

How to solve this problem?

Today, I bought a DVD drive and installed the DVD drive into my PC, then I installed Nero, and burnt the Win7 English 64-bit version ISO file on a blank DVD. I rebooted the PC and pressed F8, entered the boot menu, set DVD to boot. When rebooting, I successfully installed the English version of Win7 Professional.

I have more question to ask :

1. Why can't the ISO file not be installed from hard disk? Why can I install it when i burn the ISO file on DVD?


2. How can I build an ISO image which can be installed from hard disk?

Answer

If you already have an operating system installed on the computer
which matches your iso installation media as regarding bitness
(32-bit or 64-bit), then you can install Windows 7 directly from the iso file.

The procedure is as follows :

• Boot into the existing Windows installation


• Install a virtual disk tool such as the free version of DAEMON Tools Lite
  (refuse all adware offers when installing)


• Mount the Windows 7 iso as a virtual disk (say it is called X:)


• Open X: in Windows explorer


• Execute setup.exe

This will copy the installation files to the hard disk and continue from there.

If the above method is not convenient for you, or the bitness does not agree,
or this is a bare-metal installation,
then you must create a boot DVD or boot USB key to install.