Install Windows 7 with less than 512MB RAM

According from Microsoft site, running Windows 7 should take:
1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
If a machine with 512MB or lower RAM will run windows 7, the installer will tell that the RAM is not enough and cancele installation. Here is how to install Windows 7 on a machine with less than 512MB RAM:

1. Unzip or Mount the Windows 7 ISO

2. Download and install a dll editor, AptEdit Pro, WinHEX for example

3. Open the winsetup.dll under source folder

4. Find 77073D7801 string

5. Modify to E90400000

6. Save and quit

7. Recreate to a ISO and restart the installation