[charlesportwood]

If you're looking for a service, Browser Stack (http://www.browserstack.com/) gets the job done.

Microsoft also offers free VMs for testing IE at modern.ie (http://www.modern.ie/en-us/virtualization-tools) for Virtualbox, Parallels, and VMWare. They have 9 or so images for testing IE, ranging from IE6 on Windows XP, to IE11 on Windows 8.1.