Troilus and Criseyde - http://etext.lib.virginia.edu/etcbin/browse-mixed-new?id=ChaTroi&images=images/modeng&data=/lv1/Archive/mideng-parsed&tag=public Plain Text in original Middle English on a single page.
Troilus and Criseyde - http://www.gutenberg.org/etext/257 In plain text, or as a zip file, at Project Gutenberg.
Troilus And Criseyde - http://academic.brooklyn.cuny.edu/webcore/murphy/troilus/ Rendered into modern English spelling; this site also includes the text of Robert Henryson's "The Testament of Cresseid" and the translator's prefatory comments. All are in Portable Document Format.