Cannot Import MS Word 2010 to Robohelp 9 on Windows 7 64-bit

I am using Robohelp 9 on my Windows 7 64-bit machine. But when I try to import MS Word 2010 document, I get the following error message:

"The Import Word Document Wizard cannot locate a supported version of Microsoft Word. Please install Microsoft Word 2000 or newer."

What is the solution and why is this happening?