How to Install R
You can find the installation files and all necessary information regarding installation on one of the mirror sites of the Comprehensive R Archive Network (CRAN). Select the link for your operating system, which will take you to the download site for the latest distribution of R.
You can find detailed installation instructions in the R Installation and Adminstration manual on CRAN. For Windows, you take the following steps:
Go to CRAN, click Download R for Windows, click Base, and download the installer for the latest R version.
Right-click the installer file and select Run as Administrator from the pop-up menu.
Select the language to be used during installation.
This doesn’t change the language used by R; all messages and Help files remain in English.
Follow the instructions of the installer.
You can safely use the default settings and just keep clicking Next until R starts installing.
R exists in a 32-bit and 64-bit architecture. If you have a 64-bit Windows version, you can easily install both architectures next to each other. (The installer will do this by default.) For other systems, you can find more information in the R Installation and Administration manual.
The 32-bit version of R is perfectly fine — sometimes it’s even a bit faster than the 64-bit version. You need the 64-bit version only if you require more work memory than the 32-bit version can handle. (On Windows, the maximum is about 3GB for a 32-bit system.)
If you want to be able to personalize your R installation as explained here, you should install R outside the Program Files folder (for example, in C:R). This way, you avoid trouble with the default Windows folder protection.
Mac OS X and Linux users especially need to read the instructions on the CRAN site carefully. R can be installed on all systems, but depending on your version of OS X or Linux, you may need to follow special procedures to install R successfully. Not following these procedures could harm your system.