I have followed this blog and I am able to install Windows 7 over a PXE Server and Samba shares.
But this installation process is not completely automated. It boots the system using WinPE image created using Windows Automated Installation Kit. After WinPE image finishes loading, it shows a command prompt window on screen. Then I am mapping Windows installation sources configured on PXE Samba share directory, as a Network drive(net use z: \192.168.1.20\install\x64) and running setup.exe utility to start windows installation.
Is there any way to avoid this step and start windows installation directly?