Installing on Windows
Windows has the greatest number of client options. You can either install a console CPU and/or GPU client, or a GUI CPU/GPU client. The console clients run slightly faster as they are more lightweight, however the difference is not large enough to sway you one way or the other.
To install the GUI client, simply download the correct client for your platform from the following page:
http://folding.stanford.edu/English/Download
Run the executable that you have downloaded and it will install to your hard disk. You can then run the client by finding it in your Start Menu. Once the client has started you can configure it by right clicking on the icon in your notification area on the right hand side of your taskbar, and clicking configure. In the window that pops up, enter your user name, user key, and team number, as well as any other parameters you wish to change.
It is important to note that there are two distinct different clients for windows: the basic folding client which is located at the above link, or the High Performance Beta SMP client for Windows which will yield much more performance. The SMP client utilizes all cores of your multi-core processor, which will help you gain many more folding points, and it is highly recommended that you use this client instead of the regular one. To install the SMP client, simply download it from this page:
http://folding.stanford.edu/English/DownloadWinOther
and set it up just as the regular client. If you wish to install the console client, simply download either the regular or the SMP client from their respective links and run the installer files that you download. Then, run the executable from your command prompt by typing the path to the executable in your command prompt window. Simply set your user name, user key, and team number as well as any other parameters you wish to set. I recommend disabling CPU affinity lock, enabling all your available RAM, enabling "Big" work unit downloads, and adding the -SMP parameter if you have downloaded the SMP client. If you are able to run the SMP client, it is highly recommended that you use it, as you will earn many more points.
To install the GPU client, download it from the same page as the beta SMP client from the link above, and configure it exactly the same as the SMP client.
If you install the GUI clients, they come with a 3D molecule viewer that allows you to view the molecule you are currently folding. However, this watching the molecule fold in the 3D viewer causes a significant degradation in performance, and it is recommended that you do not leave the view open for very long.