open-ephys.github.io for the most up-to-date information.

Installing the binaries

Download the Windows binaries from this page.
Drag and drop the downloaded and unzipped folder to the location of your choice, and rename it "Open Ephys."
If you don't have Visual Studio 2015+ installed, you will need to install the redistributable from here.
Run FrontPanelUSB-DriverOnly-4.4.0.exe to install the acquisition board driver.
Double-click the "open-ephys" executable to run the application.
(Optional) If you need a debug output to troubleshoot, run the executable with --console as parameter.

Building from source

Create a GitHub account if you haven't already.
While logged into your account, go to https://github.com/open-ephys/plugin-GUI and click the "Fork" button in the upper right. You now have your own copy of the GUI repository. Any changes you make will only affect this copy. (More info on forking here.)
Make sure you have GitHub for Windows installed.
Install Microsoft Visual Studio 2019 if you haven't already.
Direct your browser to https://github.com/yourusername/plugin-GUI, where "yourusername" is replaced by your actual GitHub user name.
Click the "Clone in Desktop" button.
Create the build files for the GUI
Run Resources/DLLs/FrontPanelUSB-DriverOnly-4.4.0.exe to install the acquisition board driver. This driver should be compatible with Windows 7, 8 and 8.1, but seems to work well on Windows 10 as well.
In Visual Studio, select the open-ephys.sln file from the Build folder.
Select Build/Build Solution (or press F6) to build the GUI from source or hit the "Debug" button to build and run. (development: To run and debug the GUI from Visual Studio you must either set the "open-ephys" project as default by right clicking it and choosing "Set as StartUp project". Remember than doing so will enable running the debugger through the Debug ("play") button, but doing so will not rebuild the plugins in case that was needed. To rebuild the GUI you must still select build solution or the F6 button. Alternatively, you can run the debugger in the GUI without changing the default project by right clicking the "open-ephys" project and selecting "Debug/start new instance")
Copy Resources/Bitfiles/rhd2000.bit to the Debug/bin folder created by Visual Studio (development: this step is not needed)

Building the optional plugins

ZMQ plugins and HDF5 Plugins are no longer shipped by default with the code base and be downloaded, built and installed from their own repositories. Follow the steps in the related pages to do so.

Now you can both use the GUI and make changes to the source code. We recommend reading through the developer documentation before doing so.

NOTE: The debug version of the GUI runs really slowly on Windows. If you're doing any actual data acquisition, you should build the release version instead, which runs smoothly.

Any changes you commit can be synced with your GitHub repository through the GitHub application or from the command line. If you change something that you think would be useful for others, you can submit a pull request to the Open Ephys version of the GUI.