The situation you are encountering is occurring because as of IE 7, Microsoft introduced a special security feature called “protected mode”. When IE runs in protected mode, it and the programs it runs cannot gain write access to files and registry keys in a user's profile or system locations. This is what is causing the error dialog box to display.
This situation is not isolated to only our product but rather affects a large number of other virtual printers. Any printer that interacts with a “FILE:” port will have this issue.
In order to resolve this situation, we would suggest that you turn off “protected mode” in Internet Explorer or use other web browsers to print. Protected mode can be turned off by going through the Tools->Internet Options-> Security Tab of IE.