When you installed X6, you had the opportunity to install ghostscript and may even have done it without knowing.
To check if you have it, go to windows control panel > programs and features. If you have it it will probably appear as GPL Ghostscript in the name column.
If you do not have it, you can either go to ghostscript.com or run a Coreldraw modify installation. Ghostscript.com will get you a newer version, but they both work well with CorelDraw.