MarkdownPad has a standard freeware version along with a payware Pro one -- comparison table is at http://markdownpad.com/compare.html.
A Softpedia page and review can be found at http://www.softpedia.com/get/Programmin ... nPad.shtml.
author of http://markdownpad.com/ wrote:MarkdownPad is a full-featured Markdown editor for Windows.
MarkdownPad makes available a "portable" download package with the following caveat:
Download MarkdownPad "portable" (currently v2.5) from http://markdownpad.com/faq.html#portable.author of http://markdownpad.com/faq.html#portable wrote:Note: While the portable version doesn't require installation, it still uses Windows' local and roaming user storage for saving application settings, stylesheets, etc. This will not cause issues on access-limited systems.