MikTeX can be installed in many ways, only one of which I have found to be easy in the long term.
There are 2 kinds of MikTeX installers:
Basic Installer: Installs the basic files. Whenever any TeX file you try to compile needs an unavailable package, it will need to be installed from the Internet by using the MikTeX Package Manager.
Net Installer: This single installer is used to achieve two separate tasks:
To download the files required for a complete MikTeX system.
To install either a basic or full MikTeX system using the setup files downloaded in the above step.
I used to use the Basic Installer, but have come to loathe it! ☹ Installing packages when required is a pain since that needs Administrator privileges. Also, the MikTeX package website is sometimes offline or slow and you will be unable to install the oh-so-urgently-needed package you want.
Since, both Internet speed and disk space is cheap these days, I recommend running the Net Installer to download the entire MikTeX archive from a nearby mirror. Run the Net Installer a second time to install a complete MikTeX system from your downloaded MikTeX archive.
Tried with: MikTeX 2.9