Here yo go, to install ImageMagick and build the RMagick gem and make it all work.

Follow below steps:

1. Go here mirror images.
2. Download ImageMagick of any version except the currently latest release, which has some issues
3. Install it with options: Add to PATH and development headers. Installation path should not contain spaces.

4. In the command line type convert -version to check if everything works. It should print something like:

   Version: ImageMagick 6.6.1-10 2010-05-15 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2010 ImageMagick Studio LLC Features: OpenMP

5. Install the DevKit if you haven't already.

6. Install the rmagick gem: gem install rmagick --platform=ruby -- --with-opt-lib=c:/ruby192/ImageMagick/lib --with-opt-include=c:/ruby192/ImageMagick/include

(Making sure the paths point to wherever you installed imagemagick)

It should print

Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...

And after a few minutes if everything goes right, you should see

Successfully installed rmagick-2.13.1
1 gem installed
Installing ri documentation for rmagick-2.13.1...
Installing RDoc documentation for rmagick-2.13.1...

And that's it. Just two more links that were helpful: 1 blog and 2 blog if you still can't install

Windows 10 installation, Start Installation Wizard​​ Execute the downloaded file from your browser or by double-clicking on the filename from within Windows Explorer. The ImageMagick Setup Wizard will appear. Click on “Next>” to continue. Install from Unix Source • Install from Windows Source Chances are, ImageMagick is already installed on your computer if you are using some flavor of Unix, and its likely not installed if you are using some form of Windows.

ImageMagick For Windows, Start Installation Wizard​​ Execute the downloaded file from your browser or by double-clicking on the filename from within Windows Explorer. The ImageMagick Setup Wizard will appear. Click on “Next>” to continue. Execute the downloaded file from your browser or by double-clicking on the filename from within Windows Explorer. The ImageMagick Setup Wizard will appear. Click on “Next>” to continue. Select Destination Directory. Specify what drive and directory to install ImageMagick into. Approximately 13MB of free disk space is required to install ImageMagick.

How to install ImageMagick on Windows 8.1, as of 5/1/2017:

1. take a deep breath

2. uninstall imagemagick/rmagick/everything that's failed so far

3. make sure you have the DevKit that the accepted answer linked to

4. Don't download the current v7 of ImageMagick. I have no idea why, but it doesn't work. Instead download ImageMagick-6.9.8-4-Q16-x86-dll.exe from here

5. Install, including the headers. Since it's V6, it includes legacy utilities already so you don't have to worry about that. Install into your C: directory so there are no spaces in the path.
6. Open up your environment variables. You know, System>advanced system settings>environment variables.
7. Find PATH in system variables, edit and copy and paste the large variable value into a notepad or something so you can read it properly.
8. Find ImageMagick's path, cut it out and paste it to the front. My PATH starts with "C:\ImageMagick-6.9.8-Q16;..." If it's not there, add it yourself.
9. Update your PATH with ImageMagick at the front.
10. You should be all setup, go into command prompt and type "convert -version". Rather than a "Invalid drive specification" result which drove me insane, you should see the current version specifications.
11. Bobs your uncle, you have ImageMagick!

ImageMagick For Windows, Here yo go, to install ImageMagick and build the RMagick gem and make it all work. Follow below steps: Go here mirror images. Download  Features and Capabilities • News • Community. Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG.

There is it better described: http://www.redmine.org/projects/redmine/wiki/HowTo_install_rmagick_gem_on_Windows

ImageMagick Install Windows, Installing ImageMagick on Windows-based systems. From the Start menu select Run. In the Run program dialog box type cmd to access the console. At the prompt type: If ImageMagick is already installed, a message will be displayed with the version and copyright notices: To install ImageMagick on a windows system it is recommended that you have administration rights. The steps to take are: Download the ImageMagick binary install package from one of the ftp sites listed on the ImageMagick download page. Pick the location that is closest to you, then download the latest version. The file will be named similar to ImageMagick-6.2.2-Q8-windows-static.exe and should be found in the binaries subdirectory

this is the only approach that worked for me:

http://rails.webintellix.com/2010/01/04/how-to-install-rmagick-imagemagick-on-windows/

Installing ImageMagick, How to Install ImageMagick 7.0.2-5-Q16-x64 on Windows Video tutorial : https://​youtu.be Duration: 3:39 Posted: Jul 25, 2016 I am trying to install ImageMagick on Windows. What I did is install Windows RailsInstaller created my version and now I need to use ImageMagick but for some reason it doesn't work. I took the bin

Install ImageMagick 7.0.2-5-Q16-x64 on Windows byAO, Explorer to run it. The installation wizard will open a dialogue window. Keep clicking on Next or Install until installation is completed. Install the ImageMagick PHP extension in Windows NOTE I recently released a PowerShell module that will let you install the PHP imagick extension simply with Install-PhpExtension imagick In order to install the imagick PHP extension on Windows, you need to know the exact version of your PHP.

Use ImageMagick to quickly and easily process images for your blog , and install imagemagick on Windows 7/8/10 Download ImageMagick for your OS types Duration: 6:46 Posted: Jan 4, 2020 ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you may use, copy, modify, and distribute in both open and proprietary applications. It is distributed under a derived Apache 2.0 license.

Convert pdf to jpg using ImageMagick without Ghostscript, In order to install the imagick PHP extension on Windows, you need to know the exact version of your PHP. To do this: open a command prompt and enter these  Installing ImageMagick under Windows ImageMagick is under constant development, new versions are released roughly on a monthly basis. It is strongly recommended to use an up-to-date version of IM, especially when IM doesn't seem to perform a job quite as you expect it to do.

Comments

• Seems good but you actually need to prepend the imagemagick bin dir to path, not just add it.
• The link is now broken.
• The first one @SumitMunot
• It looks like one of the issues with v7 is that the CLI has been renamed to "magick" instead of "convert"... so that broke some things for me (finding instead system32/convert per @john-pankowicz's comment below).
• check here for mirrors with older versions imagemagick.org/script/mirror.php
• pguardiario is exactly right. There is a convert.exe in c:\windows\system32. It is for converting a FAT volume to NTFS. It expects to be passed a drive letter. That is why it says "Invalid drive specification." I put ImageMagick at the start of the path and now not only did the ImageMagick test commands work, but I was able to install the Rmagick gem with no problem.
• take a deep breath This was delightful and it worked beautifully!
• Note that link-only answers are discouraged, SO answers should be the end-point of a search for a solution (vs. yet another stopover of references, which tend to get stale over time). Please consider adding a stand-alone synopsis here, keeping the link as a reference.