CS Install double Systems on PC (Win7 & linux)

i spent almost one night to build a double-system environment. during this process, some problems have been brought up, so i'm here to make a note to log my experience.

first, my PC have already set win7 option system before. and then a CD of linux system is required.

download the fedora system image file from the http://fedoraproject.org/zh_CN/, it is convenient.
fire the data on a DVD, as the image file can't be start from a virtual driver(daemon tools)
disable the PC's security using DOS command line.
also command PC start from the DVD drive first.
make sure the initial data in the PC have already been placed in a security part, then using the partition software to open a blank hard disc part which should not be perceptive by Win7 system. this blank disc, 7G enough, will be used in the following setup.
others steps can be refer to the Help page of the fedora."installation quick start". http://docs.fedoraproject.org/en-US/Fedora/19/html/Installation_Quick_Start_Guide/s1-diskpartsetup-x86.html
now my PC can operate under two systems, which is very for my study. my English is poor, so i need to improve it. insistance makes a change. All big came from small.