Alright, I\'ve been trying to install Rmagick on a Windows 7 x64 machine pretty much all day. I\'ve checked out every single tutorial on Stack Overflow and other sites, but
I don't have enought privileges, sorry for posting my comment to Luis Lavena's answer here.
One solution that worked for me was running Luis Lavena's solution from "Command Prompt with Ruby and Rails" (from the Windows start menu). It loads all necessary configurations.