I have installed WIN 7 on my laptop, and currently I need to install other systems for test my app, Where can I find good boot loader for add/remove/ load a few systems ? Thanks.
GRUB (Grand Unified Boot Loader) can boot most any operating system. Easiest way to get it -- install Ubuntu alongside your Windows installation. That will give you a new bootloader, one more OS, and a good example of how to add further operating systems.