8/15/14 As you will read from the comments below, there came a point when the suggestions I gave here no longer work. I suggest that you download the latest version of MikTeX (2.9 as of this writing). Older versions may no longer be supported so that the “install packages on the fly” will not work (not even if you use the Package Manager). I haven’t installed 2.9 myself (due to bandwidth limitations in our on-campus internet) but the steps I wrote below should (hopefully) work as long as you have the latest versions of the needed software, which you can find here: MiKTeX, TXC.
Below are three easy steps on installing MiKTeX, LaTeX and Beamer.
1. First you need to install MiKTeX. It’s pretty much the core of the of the LaTeX system – it’s the software that actually creates the documents. Size is approximately 110 MB. Click here to download MiKTeX. The rest of the installation process is pretty much intuitive. Installation may take minutes so be patient.
2. Next you will need an environment on which to type codes. The most commonly used one is TeXniC Center (go to the download page). Once you’re done downloading, installation should be a breeze. When you first run Texnic Center, the set-up will ask you for the location of executable files. The default location should be \Program Files\MiKTeX 2.8\miktex\bin.
3. Now let’s install Beamer. Note that this only if you have an internet connection. Otherwise, you might need to download Beamer’s components at its SourceForge page (look elsewhere on how to install Beamer manually). Click Start, look for MiKTeX then go to Maintenance –> Settings. On the General tab select your default paper size, and on “Install missing packages on the fly”, choose Yes.
This option will save you from downloading all the necessary packages to install Beamer, which is kind of a hassle. Open TeXnic Center and go to File –> New. Then copy and paste any Beamer code, such as the ones here. Save the file, then click CTRL + F7 to compile it. TeXniC Center will automatically call MiKTEX install whatever package is needed.