Very helpful Artella. Your page is about *using* Haskell or GHC on Windows. That is usefully distinct from how to *build* GHC on Windows; there is a separate page on the Trac wiki about that. I’ve added a clarifying sentence to your page, and added links from each to the other. I’m cc’ing a few others who have Windows knowledge. I would love it if you guys formed a GHC-on-Windows Task Force, who tried to make sure that the Windows experience was always good. At the moment we have lots of Windows users but very few who are willing to help make it work, the recipients of this email being honourable exceptions. Simon From: Artella Coding [mailto:artella.coding@googlemail.com] Sent: 25 June 2014 11:54 To: Simon Peyton Jones Subject: Haskell on windows 7 installation instructions Hi, I saw the installation instructions in http://www.gundersen.net/haskell-on-windows/ which cover installing in windows with msys (you suggested to the author that he put the instructions up on haskellwiki). However I wanted to install with the newer msys2 (which allows copying and pasting) and had quite a few problems initially (especially when trying to build hoogle). I have worked out all the issues, and have taken the liberty of writing the instructions at : http://www.haskell.org/haskellwiki/Windows which might require further editing. It took me a whole week to sort this out and thought it might be of help to others. I found that if you don't define the MSYSTEM environment variable (if you use the "msys2_shell.bat" instead of the "mingw32_shell.bat" or "mingw64_shell.bat" then this environment variable is not defined), then when you build hoogle you get some strange linker error messages https://github.com/haskell/cabal/issues/1950 . I didnt want to make the instructions too long, so omitted any explanation of why this environment variable is needed. Cheers