If you have or had the 32bit version installed to your computer, then I recommend downloading the 64bit version from the official website. You have the possibility to replace the version in your computer with a more powerful one. A valid account is necessary to access the trial/downloads section.
Download page: http://www.borisfx.com/login/reg_form.php?action=esd_graffiti
Note: If you don't have an account, please register using the form on the right.