Installing QGIS on Windows

On Windows, we have two different options for installing QGIS. These are the OSGeo4W and the standalone installer.

The OSGeo4W installer is a small, flexible installation tool that makes it possible to download and install QGIS and many more OSGeo tools with all their dependencies. The main advantage of this installer over the standalone installer is that it makes updating QGIS and its dependencies very easy. I recommend that you use OSGeo4W where practical. You can download the 32-bit and/or the 64-bit OSGeo4W installers from http://osgeo4w.osgeo.org . You can download directly from http://download.osgeo.org/osgeo4w/osgeo4w-setup-x86.exe for the 32-bit version. If you have a 64-bit version of Windows, you can also download from http://download.osgeo.org/osgeo4w/osgeo4w-setup-x86_64.exe. Download the version that matches your operating system and keep it. In the future, whenever you want to change or update your system, just run it again.

If you prefer, you can use the standalone installer. This is one file to download (approximately 400 MB in size). It contains a QGIS release, the Geographic Resources Analysis Support System (GRASS) GIS, and the System for Automated Geoscientific Analyses (SAGA) GIS in one package. For a beginning, this is the easiest installation option.