proTeXt aims to be an easy-to-install TeX distribution for Windows, based on MiKTeX. After downloading, a wizard (available in several languages) guides the installation.
You can download the protext.zip file from CTAN; it is well over 3GB. That link will automatically choose a nearby CTAN mirror. If it doesn't work for you, please choose from the list of CTAN mirrors and navigate to systems/windows/protext in that mirror's interface.
If such a large download is problematic for you, proTeXt is also included in the TeX Collection, which you can get by becoming a TeX user group member.
Once you have the distribution, you can start the installation by running Setup.exe (if it does not open automatically). At present, proTeXt includes only 32-bit binaries, but runs fine on 64-bit systems.
proTeXt adds the TeXStudio front end to MiKTeX. If you want to see the complete contents of the proTeXt distribution, you can inspect the zip file via unzip (on any platform).
New users can find starting points for actually using TeX in this introduction to the TeX system.
All past releases of proTeXt have been publicly archived; through 2019, proTeXt includes a complete MiKTeX release. MiKTeX releases are available on github.
proTeXt's creator and principal maintainer is Thomas Feuerstack, while MiKTeX was created and continues to be maintained by Christian Schenk. Many thanks to both.