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Download.md

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 # Download and install 3D Slicer
 
 *   Latest stable Slicer release is <b>recommended</b> to use for SlicerRT.<br>These packages for Windows, Mac, and Linux can be downloaded from the [3D Slicer download page](http://download.slicer.org/).<br><br>
-*   Nightly Slicer builds can be used to access cutting edge Slicer features (the installed SlicerRT is still the officially released version).<br>These packages can be downloaded from the [nightly dashboard](http://slicer.cdash.org/index.php?project=Slicer4) (click on the yellow box icon next to the build corresponding to your platform and use the link provided there).<br>Note: Nightly builds may fail from time to time. If the current nightly is missing, it is possible to see builds from previous days.
+*   Preview Slicer builds can be used to access cutting edge Slicer features<br>These packages can be downloaded from the same the [download page](http://download.slicer.org/).<br>Note: Preview builds may fail from time to time. In that case the last successful preview build is available.
 
 # Install SlicerRT
 
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 # System requirements
 To run 3D Slicer you need the following configuration (SlicerRT extensions do not have any additional requirement):
-*   Computer with a 64-bit operating system  [required]. Note that Windows executables are created for 32-bit systems, but they are not suitable for any work that involves loading and processing of more than one volumetric image.
-*   Minimum 6GB RAM [recommended for optimal performance]
+*   Computer with a 64-bit operating system  [required]
+*   Minimum 8GB RAM [recommended for optimal performance]
 *   Dedicated nVidia GPU with 1GB RAM [recommended for 3D graphics display performance]. Note that integrated graphics cards are very slow compared to dedicated ones.
 *   Quad-core intel processor [recommended for optimal processing speed]